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• UNIVERSITY OF FLORIDA LIBRARY F 7 I 

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FLORIDA STATE GEOLOGICAL SURVEY HERMAN GUNTER, STATE GEOLOGIST . :. ... l r I 1 FIFTEENTH ANNUAL ( f 1922-1923 I ( r, I I , I ADMINISTRATIVE REPORT MINERAL INDUSTRIES PALEONrOLOGY OF NORTHEAISTERN FLORIDA CLAYS OF FLORIDA . \, PUBLISHED FOR TH E STATE GEOLOGICAL SURVEY . TALLAHASSEE, 1924 

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\ c • • • f • • •• • c • • c ( • • f , c • f ( c ( c t C> c. ( c c • ( t 0 (' PIUNT BY TRE RECORD COMPANY ST. AUCUSTINS P'LOIIlDA , c t> c • • • • c • • c c: Q t • • . ( • • , r c •• I c c ( . ( t e . ' • • • c • t • c, c , • • • • • • • • ••• • ••• • • r • •• • • • •• • r • •• • • • • • • • • • • • .. . . . & a 8 c. • • • ... t , • • •• ••• • • • •••• • • • • • .. . • •• •••• • • • • • • • • • .. . ••• 

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LETTER OF TRANSMITTAL To His Excellency, Han. Cary A. Hardee, Governor of F101-ida: Sir :-I have the honqr to subtnit herewith the Fifteenth Annual Report of Geologist. In addition to the Administrative Report, . which contains a statement of the expenditures of the Survey from J anua .ry 1, 19 ' 22, t9 July l, 1923, and a statistical summary of the mineral industries for the years 1921 and 1922, it contains a paper on the paleqn. tology of northeastern Florida by Wendell C. Mansfield of the United . States Geological Survey, and a report on the clays of Florida by Olin G. Bell of Cornell University. In the preparation of the report . op clays most of the counties . were visited and from . many of them samples were obtained. Owing to limited time for field work and to the finances of the Survey, it was not possible to collect as many samples as we would have liked, or to make chemical analyses. The investigation thus far conducted, however, shows that the State quantities of clay suitable the manufacture of common building brick, drain tile, building . tile and earthenware. The very plastic ball clays are admirably adapted to the ll?anufactttre of high-grade porcelain when mixed with less plastic clays. "vVith the decreased output of lumber in Florida and the r-ise in price, there comes an in creasing dernand fqr the more durable building materials. Clay m _ ust enter more largely into the manufacture of. brick and building tile in this State and it is not improbable that it will be used in the . manufacture of cement. Economic and industrial conditions point to a constant development of the clay industry. It is hoped that this report n1ay be the means of stimulating the cla.y industr _ ies already established and promote the bringing of others to the State. . . The uniformly cordial interest that you have shown toward the work of this is appreciated. Very respectfully, ovember, 1923. HERMAN GuNTER, State Geologist. 

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TABLE OF CONTENTS. Administrative Report . Introduction . New Survey Quarters . Work of the Survey . . Administrative Bureau of Information . Preparation of Reports Publications of the Survey . Plans of the Survey . Limestones and Marls . Peat Geography of Southern Florida Expenditures of the Survey . Mineral Production in Florida during 1921 and 1922 . PACF. 5 5 6 6 6 6 7 . '{ . 8 8 8 8 9 14 A Contribution to the late Tertiary and Quatern ary Paleontology of Nbrtheastern Florida, by Wen dell C. Mansfield . . . 25 A Preliminary Report on the Clays of Florida, by Olin G: Bell . 53 Index 261 

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ADMINISTRATIVE REPORT. HERMAN GUNTER, STATE GEOLOGIST • .. INTRODUCTION. The Florida State Survey was created by an Act of the Legislature of 1907 . The Act provided for the appointment of a State Geologist, and . his duties ; it detailed the obJect of the Survey, and appropriated $7,500 a year for its maintenance . The Act establishing Surv. ey has in no wise been changed until by the Legislature of 1923. the session of 1921 an Act was pas s ed creatirrg a Budget C?mmission for the State Florida. This . . Act made it the duty of each of the State Departments to submit an estimate of the amount neede . d f p r the two-year period beginning July 1st, 19 _ 23. The appropriation for the . maintenance of the Survey as effected hy the Appropriation Bill was increased fr _ om $7, 500 annually to $10,345. Since the publication of the Annual report the Geologi cal Survey's force has been, . in addi tion to the State Geologist, Mr. K. Cooke, Assistant, whose services terminated November 1, 1922. Mr. Olin G. Bell was employed as special or temporary assistant during the three-month period of 1922, which time was spent in the field preparatory to the report on the clays of Florida comprised in this volun1e. Mr. Strauss L. J;..,loyd also rendered a few day's service to. the field party while investigatip.g the clays of Hernando and . Citrus counties. Sam E . . Cobb, Jr. , . was employed temporarily rendered assistanc . e in cataloging specimens aJ:?.d other general office work. Mrs. Mabel rendered halitim . e service as stenographer from September, 1 922 , to March, 1923 . 

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6 FLORIDA GEOLOGICAL SURVEY-I 5TH ANNUAL REPORT NEW SURVEY QUARTERS :tJpon completion of the addition to the Building the Survey was provided space on the south side of the lower floor of the west extension. In its new location the Survey has one room 27 by 33 feet, which is used for displaying geological tnaterial and for the library. Connected with this are two rooms, the one used as office of the StatP. Ge9logist, while the other is for the Secretary. Additional room is needed, particularly for the purpose of. n1ailing and for the purpose of storage. The exhibition room is likewise too small, since there i s scarcely any space for additional exhibition cases . WORK OF THE SURVEY :-The work of the State Geologist has consisted of making plans for proposed investigations, correspondence and con ferences relating to their carrying out, the obtaining of bids for the purchase of supplie s and of printing reports, the C(l.re of the Survey prop erty, the supervision of work in progress ana of printing and distribu tion of reports , and in attendance to the usual correspondence of the office. During the years the Survey has been organized no special appro priation for the employment of a Secretary-stenographer was made . As a con s equence during much of the time no regular stenographic service, however much needed, has been rendered the Survey. By pro vision of the Legislature of 19 ' 23, effective July 1, 1923, the Survey will have the services of a full-t"ime stenographer. . -Bureau of Information:-A large part of the time of the State Geologist is taken up in answering personal and written inquiries of all kinds regarding the mineral and natural resources of the These con 1 e frotn private landow11:ers, prospective citizens, investors, railways, cities, commercial bod i es, teachers, students, and in fact, from all classes of people, both citizens and non-residents. This work is considered an important function of the Survey and replies are made as full and explicit a s po ss ible . \tV hen necessary , prin t ed reports are s ent in addi tion. The Sur vey has en1bra ced the opportuniti es for building up new enterpri s e s and to get bef o re the public data relative to the State' s res ourc es. 

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ADMINISTRATIVE REPORT 7 Preparation of Reports :-Upon co"mpletion of the field work, a large amount of office and laboratory work is necessary in order to get a report upon a given subject in shape for the press. In the case of the present report on the clays, much detailed laboratory work was necessary in order to get the results of the physical and burning tests of the several samples. Chemical analyses are frequently made and maps and drawings are to show the location of the deposits, and the arrangement or order of the manuscript must be considered, as well as the final proof reading while going through the press. The illustrations of the reports, too, are selected with care and aid in visual izing the occurrence and preparation of the natural product for the tnarket. Publications of the S U1'Vey :-The results of the investigations by the Survey are issued in the form of annual reports. These reports issued as a whole volun1e and also the papers making up the volume are bound separately. By this method anyone interested only in some particular subject treated in the whole report can obtain it by getting only the separate paper. These reports are distributed . free to all residents and to all boards of trade or corresponding bodies in the State, and to the libraries of the :State and to certain exchange libraries of the United States and foreign countries. Requests for RUblications from residents of States other than Florida should be accompanied with postage. In addition to the annual reports the Survey has issued two bulletins and twelve press bulletins. A complete list of the reports so far issued by the Survey may be had by writing the State Geologist, Tallahassee . . • I 

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8 FLORIDA GEOLOGICAL SURVEY-15TH ANNUAL REPORT PLANS OF THE SURVEY . In planning for field work regard is paid to the following: The reque s t for information along any given line and information ob tained about resources that apparently offer opportunities of develop ment. Thus the pre s ent report on the cla y s, it is thought, is very timely. It is planned to follow thi s with a report on the lime s tone s and marl s . Upon the . completion of thi s , information would be in hand relative to the cement resource po ss ibiliti e s of the State. Pe at:-A preliminary report on the p eat depo s it s of the State was publi s hed by the Survey in 1910, but the edition is now exhausted. Re que s ts are regularly being recei v ed for information, particularly as to the fuel value of our peat bog s . Investigation and report 1:1pon the peat depo s its of the State w itl) particular reference to their fuel val u e should be made. The re a re kno w n to be beds of peat in Florida that might prove of large value to local i!ldu s trie s in this respect. Their l o c a tion , extent and value should be determined. . Geog raphy of So u ther n Florida:-The the geography of Central Florida, in the Thirteenth Annual Report , has supplied jus t the information many per s ons have wanted. Work is now in progress on a similar report for Florida. 

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ADMINISTRATIVE REPORT 9 EXPENDITUR'ES OF THE GEOLOGICAL SURV EY FROM JANUARY 1, 1922, TO JULY 1, 19 23 The following itemized li s t s ho ws the expenditures of the Survey f rom January 1 , 1922, to July 1, 1923. The t otal annual appropriation during this period was $7,500. With the exception of the salary of the State Geologist, which an1ount is fixed by statute, all accounts are ap proved by the Governor and are paid on ly by warrant drawn upon the State Treasurer by the Con1ptroller, no part of the fund being handled direct by the State Geologist . All original bills and itemized expense accounts are on file in the office of the Comptroller, duplicate copies being retained in the office of the State Geolog i st. LIS1' OF WARRANTS ISSUED FROM JANUARY 1, 1922, TO JULY 1, 1923. JANUARY, 1922. M. K. Cooke, assistant, salary ..................................... $ 125.00 M. K. Cooke, assistant, expenses. .... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21.55 M. K. Cooke, assistant, auto mileage. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55.52 Fred Coll i ns, janitor services . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 0.00 George B. P erkins, rent for January. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41.66 Southern Telephone & Construct ion Co., rent. . . . . . . . . . . . . . . . . . . . . . 3.50 Yeager-Rhodes Hardware Co., supplies .............. . ....... :.... 2.65 Economic Geology Publishing Co.. .......... . . . . . . . . . . . . . . . . . . . . . . . 4 . 00 American Railway Express Co.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.15 FEBRUARY, 1922. Herman Gunter, State Geo logi st, expenses ................ .......... $ M. K. Cooke, assistant, sa lary ........................ ....... ... .. . M. K. Cooke, assistant, expens . es ................................. . . M. K . Cooke, assistant, auto mileage .......... .................... . Fred Collins, janitor services ............. . . . ...................... . George B. Perkins, office rent ..... : . .............................. . Southern Tel ephone & Construction Co ............................ . American Railway Express Co .................................. . MARCH, 1 922. Herman Gunter, State Geologist, salary for quarter ending March 85.49 1 25.00 18.75 48 . 80 10.00 41.66 3.50 2.39 31, 1922 ...................................................... $ 625.00 M. K. Cooke, assistant, salary. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 25 .00 E. H. Sellards, field expenses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 94. 00 Sam Cobb, services February and March................. . ...... . ... 14.25 Fred Collins, janitor services . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10.00 George B. Perkins, office rent....................................... 41.66 Southern Telephone & Construction Co . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.50 American Railway Express Co . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.45 W. H. May, postmaster, stamps and post office box rent..... . . . . . . . . . 21.50 W. C . Dixon, . drayage............................... ............ 1.75 T . J. Appleyard, letter heads....................... . . . . . . . . . . . . . . 4.50 Yeager-Rhodes, Hardware Co . , suppl i es . .... . . . . . . . . . . . . . . . . . . . . . . . 1.65 H . & W. B. Drew Co., supp lies. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.36 Fielder & Allen Co., supplies....................... . . . . . . . . . . . . . . . . 14.00 D. C. Heath & Co ......................... , . . . . . . . . . . . . . . . . . . . . . . . 12.00 

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10 FLORIDA GEOLOGICAL SURVEY-15TH A-NNUAL REPORT APRIL, 1922. M. K . Cooke, assistant, sa lary .......... .' ........................... $ M. K. Cooke, assistant, expenses ..... ..... ....................... . M . K. Cooke, assistant, auto mileage ............. . ................ . Sam Cobb, services .......................... ............... . . .... . Fred Collins, janitor servic es ................ ............ ........ . George B. Perkins, office rent. . .... . . . ...... . ................... . . . s outhern Tel ephone & Cons truction Co ............................ . American Express Co ................................... . . E llis, Curtis & Kooker, maps of Florida .................... ....... . Wrigley Engraving & Electrotype Co ............... • . ............. . l'v1A Y, 1922. M. K. Cooke, assistant, salary ....................... ............. $ Fred Co ll ins, janitor services ............................ : ....... . George B . Perkins, office rent. ....................... ............. . vV. H. May, postmast e r, stamps ........... . ...................... . Grant Furniture Co., letter folders . . . ............ .............. ... . Wrigley Photo Engraving Corp ................................ . . . Commercial Fertilizer, subscr iption ...... ......... ................ . University of Chicago Press .......................... . .... .... ... . McGraw-Hill Book Co ...................... . ...... ............. . Southern Telephone & Construction Co ............................ . American Railway Express Co ........ . . . ...... .............. . . ... . JUNE, 1 922 . Herman G u nter, State Geologist, salary for quarter ending June 1 25.00 25.69 72.00 8.50 10.00 41.66 3.50 3.71 1.67 16.65 125.00 10.00 41.66 50.00 2.50 4 .75 2.00 3.60 6.00 3.50 .93 31, 1922 ...... .............. . ......... ........................ . $ 625.00 Herman Gunter, State Geologist, expenses ...... ................... . M. K. Cooke, assistant, salary .......................... . ......... . M. K . Cooke ; assistant, expenses .... ............................. . M . K. Cooke, assistant, auto m il eage ..... ... .... .................. . Olin G. Bell, salary June 1 3-30 ..................... ..... . . Olin G. Bell, assistant, expenses ........ ................. . ....... . Fred Coll ins, janitor services .................................... . George B. P erkins, office rent. .................................... . Southern Telephone & Construction Co ............................ . Western Uni on Telegraph Co ................................. ... . Alford Brothers, camp suppli es .................................. . T. J . Appleyard, letter h ea d s and envelop es . . ........... . . . ....... . . Milton A. Smith, 2,000 report cards ...................... ......... . Brock-Sharp Machinery Co. , field equipment ... .. ................. . . Smedley & Rogers Hardware Co., field equipment .................. . H. & W . B. Drew Co., supplies .......... ..... . ...... ............. . }ULY, 1922 . 28.73 1 25.00 68.61 1 21.00 1 20.00 86.72 10.00 41.66 3.50 2.28 3.50 15.50 9 .00 12.44 5.00 9.43 M. K. Cooke, ass istant, salary . . . ................ : .............. . . $ 1 25.00 M. K. Coo ke, assistan t , expenses ......... -........ . . . . . . . . . . . . . . . . . . 94.20 M. K. Cooke, assistant, auto mileage............. . . . . . . . . . . . . . . . . . . 196 .80 Olin G. Bell, assistant, salary.... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 200 .00 Olin G. Bell, assistant, expenses........ ....................... . . . 147.11 L. B . Marshall, copying mineral tabulations. . . . . . . . . . . . . . . . . . . . . . . . . 15.25 Fred Collins, janitor services . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10.00 George B. Perkins, office .rent........... . . . . . . . . . . . . . . . . . . . . . . . . . . . 41.66 southern Telephone & Const.ruction Co. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.50 

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ADMINISTRATIVE REPORT City Transfer Co., Tampa, packing, shipping clay samples ....... ... $ American Railway Express Co ......... . .... ...................... . W. H. May, postmaster, stamps . ...................... ........... . W. C. Dixon, freight and drayage ............................... . The Record Co., Columbia envelopes ........................... ... . Millhiser Bag Co., cloth bags ..................................... . AUGUST, 1922. M. K . Cooke, assistant,. salary ....................... . . ............ $ M. K. Cooke, assistant, expenses .................................. . M. K. Cooke, assistant, auto mileage ............ : ................. . Olin G. Bell, assistant, salary ..................................... . Olin G. Bell, assistant, expenses ................................... . Strauss L. Lloyd, services .................................. ...... . Mrs. Lila B. Robertson, special services ........................... . Fred Collins, janitor services .................•............. ....... George B. Perkins-, office rent . ................................... -: . Southern Telephone & Construction Co ............................ . American Railway Express Co .................................... . Yeager-Rhodes Hardware Co., supplies ............................ . W. C. Dixon, freight and drayage ............. , .. ... ....... ...... . Kite Transfer, freight and drayage clay samples ................... . The Record Co ................................................... . SEPTEMBER, 1922. Herman Gunter, State Geologist, salary for quarter ending September . 30, 1922 ........................................... ............ $ Herman Gunter, State Geologist, expenses ........................ . M. K. Cooke, assistant, salary . ................................... . M. K. Cooke , assistant, expenses ................................ . . M. K. Cooke, assistant, auto mileage .............................. . Olin G. Bell, assistant, salary, September 1-12, inclusive ............. . Olin G . Bell, assistant, expenses ................................. . Mrs. Mabel Lee, stenographic services ............................. . Fred Collins, janitor services ................................... . . George B. Perkins, office rent. .................................... . Southern Telephone & Construction Co ............................ . Hill's Transfer, drayage ......................................... . Charles Williams, supplies ...................................... . American Railway Express Co ........................ . . .......... . W. H. May, postmaster .......................................... . Kite Transfer, freight and drayage ............................... . H. & W . B. Drew Co., supplies ................................... . I van A ll en-Marshall Co., supplies ............................... . The Record Co., printing ................... : .................... . The Crystal Pharmacy, photo supplies . . . .......................... . OCTOBER, 192?. Gunter, State Geologist, expenses .......................... $ M. K. Cooke, assistant, salary .................................... . hj • • Mrs. Mabel Lee, stenograp 1c services ............................. . Fred Collins, janitor services ............... : .................... . George B. Perkins, office rent ..................................... . Southern Telephone & Construction Co ................. ........... . 11 8.00 4.29 25.00 1.47 30.75 35.97 125.00 107.85 219.50 200.00 122.69 23.00 30.00 10.00 41.66 3.50 30.57 1.85 19.91 18 .92 15.00 625.00 12.20 125.00 6.25 30.14 80.00 28.23 27.00 10.00 41.66 3.50 2.00 1.75 2.46 31.50 11.00 1.84 836.75 6.74 175.06 125.00 30.00 10.00 41.66 3.50 

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12 FLORIDA GEOLOGICAL SURVEY-I 5TH ANNUAL REPOR'l' W. C. Dixon, freight and drayage ................................ $ 8 .50 A. Hoen & Co., geologic map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 640.00 McGraw-Hill Book Co., Inc., book. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 .00 Leslie Tyl er, freight and drayage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32.12 W. H. May, postmaster. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25.00 H. R. typewriter repair and suppli es........ ....... . ...... 1.75 American Railway Express Co.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15.45 1922. Herman Gunter, State Geologist, October salary .... .... ............. $ 208.33 Herman Gunter, State Geologist, salary. . . . . . . . . . . . . . . . . . . . . . . . . . . . 208.33 Herman Gunter, State Geologist, expenses. . . . . . . . . . . . . . . . . . . . . . . . . . 32.82 Mrs. Mabel Lee, stenographic services. . . . . . . . . . . . . . . . . . . . . . . . . . . . 30.00 Fred Co lli ns, janitor services . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10.00 George B . Perkins, office rent. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41.66 Southern Tel ephone & Construction Co. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.50 Grant Furniture Co., supplies.................................... 2.50 Leslie Tyler, freight and drayage ................... . . . . . . . . . . . . . . 68.82 Engineering & Mining J ournai-P. ress, subscr iption. . . . . . . . . . . . . . . . . . 4.00 J obn W il ey & Sons, . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . . . . 3.50 The Science Press, publication . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10.00 University of Chicago Press, publication............ . ............... 2.10 DECEMBER, 1922. Herman Gunter, State Geologist, salary .................... . ....... $ 208.34 Herman Gunter, State Geologist, expenses. . . . . . . . . . . . . . . . . . . . . . . . . 102.84 Mrs. Mabel Lee, stenographic services. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30.00 Fred Collins, janitor services . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10.00 George B. Perkins, office rent ...... ...... . : ................ . . . . . . . . 41.66 Southern Telephone & Construction Co . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.50 W. H. May, postmaster. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26.50 T. J. Appl eyard, stationery . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.75 American Railway Express Co..................................... 3.29 American Peat Society, subscription. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.00 American Philosophical Society. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.08 The Ora Neff Co., supplies ......•...... . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.86 JANUARY, 1923. Herman Gunter, State Geo l ogist, salary. . . . . . . . . .................. $ 208.3 3 Mrs. Mabel Lee, stenographic services ... ......... . . . . . . . . . . . . . . . . . . 40.00 Fred Collins, janitor services . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10.00 George B . Perkins, office rent. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41.66 Grant Furniture Co., supp li es . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.25 American Railway Express Co.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 .35 Doubleday, Page & Co., publications . ............. .'. . . . . . . . . . . . . . . . 10.00 W. S. Brown, compass ............................ : . . . . . . . . . . . . . . . . 2.11 Warren K. Moorehead, publications........... .............. ...... . 9.18 Dixon's Transfer, moving office and mus e um supplies. . . . . . . . . . . . . . . . 61.00 FEBRUARY, 1923 . Herman Gunter, State Geologist, salary .............. ......... . . .. $ 208.33 Mrs. Mabel Lee, stenographic services. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40.00 Fred Collins, janitor services . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10.00 Grant Furniture Co. , supplies. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.50 Southern Telephone & Construction Co.. . . . . . . . . . . . . . . . . . . . . . . . . . . 3.25 Weekly Naval Stores Review, publication. . . . . . . . . . . . . . . . . . . . . . . . 3.25 Economic Geo logy Publishing Co., subscription. . . . . . . . . . . . . . . . . . . . . 4.00 

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A DlVII N I STRA1'IVE R EPORT 13 MARCH, 1923. Herman Gunter, State Geologist, salary ................ .. : ......... $ 208.34 Mrs. Florence M. Epperson, special stenographic services............ 13.00 Fred Collins, Janitor services. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10.00 Southern Telephone & Construction Co., balance on April. . . . . . . . . . . . 1.00 W. H. May, p ostmaster............................................ 26.50 W. L : Marshall, repairs on shelving.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.00 American Railway Express Co ....... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.22 APRIL, 1923. Herman Gunter, State Geologist, salary ............................ $ 208.34 Mrs. Florence M. Epperson, special stenographic services. . . . . . . . . . . . 7.80 Fred Collins, janitor services . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10.00 Southern Telephone & Construction Co.. . . . . . . . . . . . . . . . . . . . . . . . . . . 3.25 T. J. Appleyard, printing .................................. :...... 18.75 Commercial Fertilizer, subscription. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 . 00 MAY, 1923. Herman Gunter, State Geologist, salary ........................ : .. $ Herman Gunter, State Geologist, expenses ........... .............. . Southern Telephone & Construction Co ............................ . Fred Collins, janitor services . .......... .... ..................... . T. J . Appleyard, envelopes, stationery, etc ........................ . W. H. May, postmaster ..... : .... ... .................... .......... . American Railway Express Co .. .............................. ... . Grant Furniture Co., 6 s hades ................................... . . University of Chicago Press, Journa l of Geology . ..... ............ . Carnegie Institution of Washington, publication ....... . . .......... . JUNE, 1923. 208.3 3 22.15 3.25 16.00 72.15 40.00 3 .7 8 42.00 3.60 3.50 Her{llan Gunter, State G e ologist, salary ........................... . $ 208.33 Herman Gunter, State Geologist, expenses. . . . . . . . . . . . . . . . . . . . . . . . 25.72 Sam E. Cobb, Jr., services. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65.00 Fred Collins, janitor services ....... . ............................. 10.00 Southern Telephone & Construction Co ........ . ... : . . . . . . . . . . . . . . . . 3.80 W. H. May, postmaster. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51.50 State Road Department, blue printing. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.20 Underwood Typewriter Co., balance on new machine................ 69.10 Maurice-Joyce Engraving Co., half-tones . . . . . . . . . . . . . . . . . . . . . . . . . . 234.93 D. A. Dixon Co., supplies. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13.40 

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14 FLORIDA GEOLOGICAL SURVEY-15TH ANNUAL REPORT STATISTICS ON MINERAL IN FLORIDA DURING 1921 AND 1922 COLLECTED -IN Co-OPERATION BETWEEN THE FLORIDA GEOLOGICAL SURVEY, THE UNITED GEOLOGICAL SURVEY, AND THE U. S. CENSUS BUREAU The total value of the n1inerals produced in Florida during 1921 vvas $12,986,699 . This repre s ents a very decided decrea s e in total va lue of _ production over that of 1920, the reduction being n1ainly accounted for in the decreased output and value of pho s phate. For 19 22 the total minera l production value reached $ 11, 445, 073. The continued s light decrease i . n the production and value of phos phate was somewhat offse1 by the increased production and value -of all of the other mineral in dustries of the State. BALL CLAY OR PLASTIC KAOLIN This high-grade clay was discovered in Florida near Lake Lake County,* and Mr. Lawrence C. Johns on, of the United States Geological Survey, is credited with first reporting it s occurrence.t A record of the beginning of mining is contained in the Mineral Resources of the United States for the year 1893, page 614 . An interesting fact in this connection is that the Edgar Plastit Kaolin Company, of Me N.J., who were among the first to mine this clay in . Florida, have continued to mine through the intervening years and are heavily int . er ested in properties in Putnam and Lake counties. Mining has been carried on continuously since the year above ' mentioned and the ball clay industry of Florida has continued to incre ase in importance. The Florida ball clays mined at Edgar, Putnam County, and near Leesburg, Lake County, are the pures t found in this The clay occurs intimately with coarse sand and quartz pebbles, these latter I ' • forming the larger percentage of the mass. The only treatment in the . process of refining is that of washing, which remove s the sand and •u. S. Geol. Surv., Min. Res. of the U. S., 1.889 and 1890, p. 441, tlbid, Min. Res., 1891, p. 507, 1893. 

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STATISTICS ON MINERAL PRODUCTION 15 pebbles .. The washed clay is shipped to northern potteries where it i s used in the manufacture of the highe . r grade o f white wares. Although . . produced commercially in only two counties of the State, the s e clays are distributed thr-ough the central penin s ular portion of Florida and to some e x tent in northern and western Florida. The value of the output is not given s eparately, but is included with the total value of the mineral products of Florida. The following com panies in 1922: Edgar Plastic Kaolin Company, Metuchen, N. J., and Edgar, Fla. Florida China Clay Corp . , 640 N. 13th St., Easton, Pa., and Leesburg, Fla. Lake County Clay Co., Metuchen, N.J., and Okahumpka, Fla. BRICK, TILE AND POTTERY The greatly in c re as ed activity in building throughout the State is reflected in the increa s e in production of brick and tile b y the s everal plants operating in Florida 1921 and 1 922 . The tota.J number of common brick manufactured in Florida during th e latte r year, as re ported b y the produ c er s to the Florid a G e olo g ic a l Survey, was 26,296 ,000. Two concern s report the produ c t io n of face-brick and one t he manufacture of building tile. The total value of brick, tile and potter y product s in 1 9 '22 i s g iven at $ 2 0 7,4 49. The following firm s manufactured brick and tile during 1922: ., Barrineau Bros . , Quintette, Escambia County . ..,. v]. M . & J. C. Craber, Campville, Alachua Comity . . M . Dav i s , La w r e nce, Gadsd e n C ounty, ( P. 0 . Ocklo cknee) . y.Dolores Brick Co., Molino, Escambia County. Industrial School for Bo ys, Marianna, Jackson County . .Gamble & Stockton Co., Jacksonville, Duval County. 'Glendale Brick Works, Glendale, Walton County. . 1 G. C. and G. H. Guilford, Blountstown, C a lhoun County. -vW. J. Hall & Son, Chipley, Washington County . -v Hull & Cowan Co., Callahan, Nass a u Coupty. v-Key stone Brick Co . , Whitney, Lake County. Morris-Blumer Co . , Brooksville, Hernando County. (Tallahassee Pressed Brick Co., Havana, Gadsden County . -. There were two plants in Florida during 19 22 that manufactured d e corated vases and other pottery. These were : The Graack Pottery, Bradentown, and the Orlando Potteries, Orlando. 

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16 FLORIDA GEOLOGICAL SURVEY-15TH .ANNUAL REPORT DIATOMACEOUS EARTH This material, deposits of which are located in Lake County and mined several years ago near Eustis, has not been produced in Florida for several years. Renewed activity in diatomaceous earth deposits of Lake County is shown by the organization of The Florida Diatomite Company . , of Clermont. Samples of this earth have been received from Mr. C. Lindley Wood, President of the company named, and from these the is shown to be of high quality. A sm all samp le of both the crude and the burned earth was subm itted to Dr. Albert Mann, Dia tomist, Carnegie Washington, and the following paragraphs are quoted by permission.* "Your sample, when freed from organh.: matter, is a pure fresh-water diatom material of recent origin, practically free from any clay, sand, iron or other deleteri ous material. The different species of diatoms composing it vary considerably in size, contrasting thereby with such homogeneous diatom earths as those from Nevada, etc. This may be an advantage or a disadvantage according to the commercial purposes to which it is put. "As the ratio of organic matter to diatom silica is unusually Low I think it would be a profitable substance to put on the market. " FULLER'S EARTH The demand for fuller's taith in 1922 was more active than during the year 192'1. The output of this product in 1922 was second only to the output in 1920, thii banner year of the fuller's earth industry in Florida. According to published statistics by the United States Geologi cal Survey, Florida is credited with a production of 64,122 short tons, valued at $1,122,940, or an average of $17.51 a ton.t According to the same this was 46 per cent of the total output of this earth in the United States and 49 per cent of the total value. The following companies reported production of fuller's earth in 1922: Attapulgus Clay Company, Ellenton, Manatee County. Floridin Co., Quincy and Jamieson, Gadsden County. Fulier's Earth Company, Midway, Gadsden County. Manatee Fuller's Earth Corporation, Ellenton, Manatee County. *Letter of Sept. 20, 1923. tU. S. Geol. SurV., Min. Res : , 1922, Pt. II, p. 70, 1923. 

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STA1'ISTICS ON PRODUCTION 17 ILMENITE Ilmenite was recovered from the beach sands of the Atlantic Coast at M ineral City, near Pabl o Beach, Duval during 19 22. Messrs . Buckman and Pritchard, Inc., who formerly operated the plant, have sold their intere sts to the National Lead Company of New York. The output and value of ilmenite cannot be given s eparatel y without dis clo sing individual production, but it is . included in the total of the State. LIMESTONE, AND FLINT The increased activity in ro"ad building in Florida has resulted in a largely increased output of l imestone and crushed flint rock. The total amount of lime s tone, as reported by the seve ral producers, sold in F lorida during 19 22 _'was 656,910 tons valued at $622,378. The variou s purposes for which this limestone was used were: road metal; railroad balla st; agricultural purposes; rock for foundations, sea walls and s imilar work and other miscellaneous uses. To the above total should be added the amount of lime and of crushed flint rock which brings tl:E totai production of lim estone, quick-lime, hydrated lime and crushed flint rock to 824,150 tons, valued at The companies operating in 19 22 were: Blowers Lime and Phosphate Company, Ocala. Brooksville L ime , Fert.ilizer and Crushed Rock Co., Brooksville. Commercia l Lime Company, Ocala and Reddick. Crystal River Rock Co., Leesburg and Crystal River. Cummer Lumber Co., Newberry and Kendrick. Carl H. Fay, Cocoa . F lorida Hard Rock Corporation, Ocala. Florida Lime Compa n y, Ocala. The Maule-Ojus Rock Company , Ojus. Oakhurst Lime Company, Ocala. Ocala Lime Rock Company, Ocala and Kendrick. Ojus Rock Company, Ojus. F . F. Smith, Volusia. State Road Department of Florida, Tallahassee and Pineola. A. T. Thomas Company, Ocala. Volusia Coquina Rock Company, Volusia. PEAT There was only one plant that reported production of peat in Florida for 1922. The u se for which this peat was sold is reported as for fuel purposes. The total production and value is included w ith the total for the State. The operator reporting production was Mr. Robert Ranson, St. Augustine. 

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18 FLORIDA GEOLOGICAL SURVEY-15TH ANNUAL REPORT PHOSPHATE The year 19 20 is the record year for th . e phosphate indu s try both in the quantity produced and in value. Following that year came one of depression which was due largely to the European s ituation a nd pos sibly to some extent al so to the large output during 1920. The t ota l shipment of phosphate during 192 1 was 1, 780,028 lon g tons with a total valuation of $ 10,431 ,64 '2. This is 1 ,589,356 long tons le ss than the output for 1920 and a decrease in value of $9,032,720, or a reduction of about 45 per cent in output and of about 46 per cent in value . The year 1922 is marked by an increase in production of both the hard rock and pebble rock varieties and with only a very sma ll output of soft phosphate. In value, however, there was a decided reduction. The total shipments of phosphate from Florida for 19 22 were 2,058,593 long ton s valued at $8,347,522. This i s an increa se of 278,565 long tons or about 14 per cent in production but a decrease in total value of $2,084,120 or about 19 per cent. The followin g table gives the production and value of the four varieties of pho sphate rock produced in Florida for the yea rs 1900 to 1922, inclu s ive. Since the beginning of phosphate mining in 1 888 to the clo se of 19 22 Florida has produced 44,078,5 19 lon g ton s with a total valuation of $ 1 75,097,242. These figures are in accordance with :statistics collected b y the United States Geological Survey and the Florida Geological Survey. The chart on page 20, prepared by Dr. R . M. Harper, graphically illu strates the production of phosphate in Florida from the beginning of mining in 1 888 to There is al so indicated the causes of marked decline in the production for certain years such as for in s tance, the freeze of 1895, the panic of 1 907 , the World War, 191 4 to 1918, the strike in the Florida pebble phosphate fields, 1919, and the depressed European conditions following the World War, 1921 and 1922. 

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PRODUCTION AND VALUE OF PHOSPHATE RocK IN FLORIDA, 1900-1 922. (Long Tons) Land Pebble Hard Ro ck I Rive r Pebbl e Year Quantity I Quantity I V alue 190 0 .. 221)4 0 3 $ 19 01.. 247,454 660,702 190 2 .. 350,991 8 10,79 2 1903 . . 390,882 885 ,4 2 5 1 904 .. 460,834 1,10 2,993 1905 .. 528,587 1 ,0 45,113 1906 . . 675 ,444 2,029,202 1907 .. 675, 024 2,376 ,261 190 8 . . 1, 085, 1 99 3,885, 04 1 1909 .. 1,266, 117 4,5 14, 968 . 1 9 1 0 .. 1 ,629,160 5,595,947 1911 . . 1 ,992, 737 6,7 1 2 , 189 1912 .. 1,913,418 6,1 68,129 1913 • . • 2,055,482 6,57 5,810 191 4 . . 1 ,829,202 5,442,547 1 915 . . 1 ,308 ,481 3,496,501 1916 .. 1 ,468,758 3,874,410 1 917 .. 2,003,991 5,305, 1 27 1918 .. 1,996,847 5,565,928 1 919 .. 1,360,235 5,149, 048 1 920 .. 2,955,182 14,748, 620 1 921.. 1 ,599,835 8,604,818 19 22 .. 1,870,063 7,035,821 (a) Included i n land pebble. ( b ) Included in hard rock . 424,977 457,568 429,384 412,876 531,081 5 77,672 587,598 646,156 59 5,743 513,585 438,347 443,511 4 93,48 1 489 , 794 309,689 50,130 47,087 18,608 62,052 285,467 400,249 17 5,774 1 88,084 Value Quantity I V a lue $2 , 229, 373 59,863 $ 141,236 2,393 ,0 80 46,974 105,691 1,7 43,694 5,055 9,711 1,988,243 56,578 113,156 2,672,184 81,030 199 , 127 2,993,732 . 87,8 47 213,000 3,440,276 41,463 116,000 4,065,375 36,185 136 , 1 2 1 4,566,018 11,160 33, 480 4,026,333 ...... ... . . ....... .. 3,051,8 2 7 ....... ... . ....... . . 2,761,449 (a) (a) 3,293,168 (a) (a) 2 , 987,274 (a) (a) 1, 9 1 2, 197 (a) (a) 265 , 738 .. ........ . . ....... . 295,755 ... ... .... . ......... 159,366 .......... . . ........ 3 77,075 .......... . ......... 2,452,563 ... ...... . . . ... . ... .. 4,525, 191 .. . . ...... . .... . . .. . 1,806,671 ..... . . ... . . ........ 1,3 08 ,201 1 ••••..••.• ..... .. . .. Soft Rock \ Toml \ Quantity I V alue Quantity Value . .... . . . .. $ ......... 706,243 $2,983 , 312 .......... . . . . . . . . . . 75 1,996 3,159,473 . ... ...... . .. .. .. . .. 785,430 2,564,197 ...... . ... . ... . . .... 860,336 2 ,98 6,824 . . ....... . . ...... . .. 1 ,072,951 3,974,304 .......... . . . ... . . . . 1,194,106 4,251, 84 5 . . . . .... . . . ... ...... 1,304,505 5,585,578 .......... . . . . . . . . . . 1,357 ,365 6,577,757 .......... . ... . . . ... 1,692, 10 2 8,484,539 . .... . .... . ......... 1,779,702 8,541, 30 1 . .. . . . .... . ... ...... 2 , 067,507 8,647,774 .. ........ . .. ... . .. . 2,436 , 248 9,473,638 .. .. .... .. . ...... ... 2 , 406,899 9,461,297 .......... . ......... 2 , 545,276 9,563,084 .... . . . . . . . .... ..... 2,138 ,891 7,354,744 . ......... . ........ . 1,35 8 ,611 3 ,762, 239 (b) ( b ) 1 ,515,845 4,170,165 (b) (b) 2,022,599 5,464,493 8,331 147,103 2,967,230 6,090,106 14,498 1 96,3 1 8 1 ,660,200 7 ,797,92 9 13, 953 190,551 3,369,384 1 9,464,362 4,419 20, 153 1,780 , 028 1 0,43 1,6 42 446 3,500 2,058, 593 8,347,522 (/) I-) > H (/) H () (/) 0 z H z l' "'d g c::: () H 0 z <:C 

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PRODUCTION OF PHOSPHATE ROCK IN FLORIDA 3,000.,000 2000000 . 1888-1922 (LONG TONS) LEGEND HARD ROCK --•• -• • ---• --• ' •-• •---• • --II II----w WORLD WAR (EURO P) ------------.. ----------. --.. ---. sorT ROCK. Pf66LE -RtVR PL . I 000 ooo ..J ------• -L :J • --------• , .. ILl !r \4.. -:-. U! :> v I.J -z .I. 0 t-Ij. s H 0 0 t"-1 0 0 H () > t"-1 Ul c I<! I H U\ > z 2! C! > . . t"-1 t=1 1-d 0 1-j 

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STATISTICS ON MINERAL PRODUCTION 21 LIST OF PHOSPHATE MINING COMPANIES OF FLORIDA1 1922 Acme Phosphate Co ......... . . ...... Morriston, Fla. American Hard Rock Phosphate Co ... Floral City, Fla. American Agricultura 1 Chemical Co ... 2 Rector St., New York, N.Y., and Pierce, Fla . . American Cyanamid Co .............. 511 Fifth Ave., New York, N. Y., and Brewster, Fla. Armour Fertilizer Works ............ 209 W. Jackson Blvd. , Chicago, Ill., and Bar-tow, Fla. Peter B. & Robert S. Bradley ....... . 92 State St., Boston, Mass., and Floral City, F la. J. Buttgenbach & Company ........... 22 Ave. Marnix, Brussels, Belgium, and Dun-nellon, Fla. C. & J. Camp ....................... Ocala, Fla. Charleston, S. C., Mining & Manufac-turing Co ...... . ................... Richmond, Va., and Fort Meade, Fla. Coronet Phosphate Co ....... ........ 99 John St., New York, N. Y., and Plant City, Fla. Cummer Lumber Co ................. 453 St. James Bldg., Jacksonville, F l a., and Newberry, Fla. Downing Phosphate Co., Lessee, (Norfleet & Williams, Prop's) . ...... Newberry, Fla. Dunnellon Phosphate Co ............. 106 E. Bay St., Savannah, Ga. , and Dunnel-lon, Fla. Florida Phosphate Mining Corp ..... . . P . 0. Box 1118, Norfolk, Va., and Bartow, Fla. Franklin Phosphate Co., (P. J. & J. H. Norfleet, Lessees ) ... . . . . . . ........ Newberry, Fla. Holder Phosphate Co .............. . . . 3352 Jefferson Ave., Cincinnati, Ohio, and Inverness, Fla. Independent Chemical Co., Inc ....... 33 Pine St., New York, N. Y., and Bowling Green, F l a . . International Agricultural Corp ....... 61 Broadway, New York, N.Y., and Mulber-ry, Fla. Loncala Phosphate Co ............... Ocala and Floral City, Fla. Mutual Mining Co ................... 102 E. Bay St., Savannah, Ga., and Floral City, Fla. Morris Fertilizer Co ....... . ........ 801 Citizens & Southern Bank Bldg., Atlanta, Ga., and Bartow, Fla. Otis Phosphate Co., (P. J. & J. H. . Norfleet, Lessees ) ................. Benotis, Fla. Palmetto Phosphate Co ............... 2 Rector St., New York, N. Y., and fierce, Fla. Phosphate Mining Co ................ 110 William St., New York, N . Y., and Nichols, Fla. Peninsular Phosphate Corp ........... 215 Fourth New York, N. Y., and Ft. . Meade, Fla. Seminole Phosphate Co .......... ..... Croom, Fla. Southern Phosphate Development Co ... Inverness, Fla. Southern Phosphate Corp ............ 96 Wall St., New York, N.Y., and Mulberry, Fla. . Swift & Co ......................... Union Stock Yards, Chic ago, Ill., and Bar-tow, Fla. 

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22 FLORIDA GEOLOGICAL SURVEY-15TH ANNUAL REPORT SAND AND GRAVEL The sand produced i n Florida is used principally in building for mixing in concrete and mortar. Other reported uses are, paving or road making and sand . The gravel is reported as being used only for paving and road making . The total production of sand and gravel in 1922 was 2 4 6,849 short tons, valued at $147,924 . Acme Sand Company, Leesburg. Escambia Sand and Gravel Company, Flomaton, A l a., and Tarzan, Fla. Crystal River. Rock Company, Crystal River and Leesburg. Florida Gravel Company, Quincy and River Junction. Interlachen Sand and Gravel Company, Interlachen. Lake Weir Washed Sand Company, Ocala. Leesburg Sand and Supply Company, Leesburg . Tallahassee Pressed Brick Company, Havana. Tampa Sand and Shell Company, Tampa. White Sand Company, Orlando. A. T. Thomas Company, Ocala. SAND-LIME BRICK Two companies were active l y engaged in the manufacture of sandlime brick in Florida during 1922 . The production and value is included in the _ table showing the total mineral production of the State for the years 1921 and 1922. The reporting production were: Bond Sandstone Brick Company, Lake Helen. Plant C ity Brick Company, Plant City and Tampa. 

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STATISTICS ON MINERAL PRODUCTION 23 WATER There was a decided increase in the output and in the total value of mineral waters so ld in 19 22 over that of 19 21 . Sales were reported from nine spring s in the State and the total sales were 1,004,984 gallons with a valuation of $57,305. Among the producers of mineral waters in • Florida are the following: Name of Spring Location Crystal Springs ..................... Crystal Springs, Pasco County. Espiritu Santo Springs . ...... ....... Safety Harbor, Pinellas County. Elixir Springs ....................... Green Cove Springs, Clay County. Flamingo Water Co ................. Orange City, Vol u sia County. Good Hope Mineral .............. .. J acksonviiie, Duval County. GraRock Well ..................... Miami, Dade County. Heilbronn Springs ................... Starke, Bradford County. Purity Springs ............... ... .. .. Tampa, Hillsboro Co\}nty. Panacea Mineral Springs .... ........ Panacea, Wakulla County. Wekiva Springs ..................... Apopka, Orange County. Hampton Springs ................... Hampton Springs, Taylor County. Newport Springs ........ ........... Newport, Wakulla County. White Sulphur Springs .............. White Springs, Hamilton County. Wi-Wauchula Springs ............... J acksonviiie, Duval County. SUMMARY OF MINERAL PRODUCTION IN FLORIDA FOR 1921 AND 1922 1921 1922 Mineral Product Quantity I Value Quantity I Value Phosphate (Long tons) Land pebble •..................... Hard rock ....................... . Soft rock ........................ : . Total Phosphates ............. . Ball Clay, Fuller's Earth, P e at, Zircon, Ilmenite (Short tons) ......... . Lime, Limestone and Flint (Short tons) Common Brick, Pottery, Tile and Sand-Lime Brick .................. . Sand and Gravel (Short tons) ....... . Mineral Waters (Gallons) ...•..•..... Total Value •................. 1,599,835 $ 8,604,818 1,870,063 $ 7,035,821 175,774 1,806,671 1 88,084 1,308,201 4,419 20,153 446 3,500 1, 780,028 10,431,642 2,058,593 8,347,522 86 , 294 1,504,574 107,684 1,666,260 589,359 . 638,272 824,150 857,913 . . . . . . . . . 286,522 . . . . . . . . . 368,149 160,445 97,324 246,849 147,924 321,472 28,365 1,004,984 57,305 $12,986,699 . $11,445,073 

PAGE 29

• . t A CONTRIBUTION TO THE LATE TERTIARY AND QUATERNARY PALEONTOLOGY OF. NORTH EASTERN FLORIDA.* BY WENDELL C. MANSFIELD. • • • • • •• • •• • • • •• . . . .. . . : : . . . . . . . . ... .. .. . . .. . . .. . . . . . . .... .. . . . . -• • • • ••• . . . : : . . . . •• • • • •• . . . . . . ... . . .. ' . . . . . . . . . , . . , , , , , • ••••• • • • • • •• • •• ... "• . • • • •' • • • • e • • • • • • • • • • • • • • • • . .. ,• , . ( , , ) , , , ' 0 ••••• • • . .. . • • • • • • • • • • • • • • ee I •" • . a • I ••• ,. •• .-• • • • !J It, • • ) ) 0 II •Published by permission of the Director of the U. S. Geological Survey. 

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-CON'fEN'l'S. Introduction . . . Sources of the fossil material . Faunal list and distribution of species from all localities . Nashua marl . • • N arne and original description Lists of species from the Nashua marl . Age of the Nashua marl . • Miocene at Kissimmee . . Late or early Pleistocene deposits • ;pleistocene deposits . • • Comments oo faunas from formerly reported localities New lists of species from two localities 27 28-29 (Insert) 29-35 29-31 31-34 34-35 35-37 37-40 4042 40-41 • 41-42 Cprrelation table . • • • • • • • • • • • 43 List of stations with age assignments • 44 • 45-48 ' Descriptions of new species I ... I r,. { I • {} I t. ('I C I (tl. C • • • I 11 ustra tions -' ( . r, <, . . -. . ) . . • • f \ (. f f.., I e I ' e f (. e ' e 49-51 0 0 0 (\ ' . CJ " U " ') ' •"" (' 0 (J 0 • (J () () 0 ' 'J t) I) ., \1 ( (,1 IJ (I 0 I: (J (• f... (; f) (I ( \l ho!J'Ir. noo . o ? c fl o r v o , . ,; c l' r. .. \ ., t ..,u I ' ... I ' I) \ 0 I) (J I • 0 0 > ,, : • o :0' 0 r) o o1\, o _, r, o I) ')0 0 ' J ( ' ., (1 ,, 

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IN,TRODUCTION. After examining the molluscan fauna from the Pliocene calcareous marls in the vicinity of DeLand, Florida,1 a more extensive comparison of this fauna .and other faunas in northeastern Florida with that at the type locality of the Nashua marl seemed desirable. At some of the localities _ considered in this paper the number rep resen . tative forms is small and at other localities many of the fqssils are. brq ken . It is h o ped that future work in this field may supplement these collections . Although some of the results obtained are not .altogether conclusive, . it is believed that an advance made in. the study of the relationship of the molluscan faunas of this part of the St"ate. lFJa. State Geol . Survey, 11th Rept . , pp. 111-123, 1918. 

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28 FLORIDA GEOLOGiCAL. SURVEY-15TH ANNUAL REPORT . SOURCES OF THE FOSSIL MATERIAL The . collections considered. in this paper are in the U. S. N atiorial Museum, and were made by Dr. T. 'Wayland Vaughan of the U.S. Oeol. Survey, Dr. E . . H. Sellards, then State Geologist of Florida, and Messrs. Geo. C. Matson, Frederick G. Clapp, and Otto Veatch. Most of the material was collected in Putnam and Volusia counties; but one collection came from St. Mary's River at the north, three from the vicinity of Kissimmee, Osceola County, and four from localities along the Atlantic coast, between Daytona and Eau Gallie . . A few species from D eLeon Springs were determined by Dr. Wm. H. Dall, and are mentioned in his work on the Tertiary fauna of Florida 1 • Specific identificati _ ons of many of the fossils were made by Dr. T. Wayland Vaughan, and listed in the Second Annual R eport of the Geological Survey, 1909. In working over the material, some of the specific identifications were changed, others queried, and some forms determined. The following are the fossil localities considered in this paper; each collection has been given a U. S. Geological Survey station number . _ :which precedes the description of the locality: . 4837-Two miles southeast of Eau Gallie, on peninsula south of point of Merritt's Island, Fla. Geo. C. Matson, collector. 4865-River bank, south of Nashua, Putnam Co., Fla., fossils from 15 ft. of white shell marl. F.G. Clapp, collector. (Type locality of the Nashua marl.) . . 4866-0ne-half mile above A. C. L. R. R. bridge over the St. Johns River, Putnam Co.; vertical cliff three to eight" feet above high-water level. F. G. Clapp, collector. 5003-In a ditch 4 miles west of Eau Gallie, Brevard Co., Fla. Geo. C. Matson, collector. 5008-East side of St. Johns River, five miles below the Sanford rail road bri " dge, Volusia Co., Fla. Geo. C. Matson, collector. 5009-East side of St. Jphns River, 7 miles below the Sanford railroad bridge, Volusia Co., Fla. Geo. C. Matson, collector. 5010-About half a mile south of DeLeon Springs station, Volusia Co., Fla. Eleven to seventeen feet below the surface. F. G. Clapp, collector. 5011-Half a mile north of R. R. station, Orange City, Volusia Co., Fla. F. G. Clapp, collector. . 5012-Seven miles west of Titusville, Brevard Co., Fla. Geo. C. Matson, collector. 5016-Deep well at Kissimmee, Osceola Co., Fla. Fossils obtained at a depth of 65 to 100 feet. C. 0. Newlands (driller). 5017-Near Michael's marlpit, one mile south of" point, Daytona, Volusia Co., Fla . . Geo. C. Matson, collector. 5019-A quarter of a mile south of railroad station, Orange City, Fla. Thirteen feet below surface. F. G. Clapp, collector. lWagner Free Inst. Sci., Vol. III, 1890-1903. .. 

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.. f 

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FAU NAL LIS T A N D DISTRIBUTION OF S P E CIES F RO M ALL LOCAI.ITI8S GASTROPODA . . " . . .. 'tl"tt 1: ;: .... U') • 0 s '0 u; • 0 " I . " T . . "' Jl:! p:; ...: .:::s tri p;: !;' Gl '2 '2 ;:$! Q .2 . • E c c e .... dd;:'-= --oocn--ii g < :;; ] ] c .. ::: ... .., ..... . r&l z < 1&1 ... too Q ..; . . . . . -.., g e i: ao co o o o o d ...,. .... ... ... ... ... 5 s "' 0 " ' "' 5 tJ 1. "' e - • II> " . . t :ij " . " 3 0 e:= --:> '"' -c ,.; -c + Actrean punctostrintus Lea ...................... . Acteocina canalic'ulata (Say) .. : ............• ..... I . I .;: 1 + Terebm co nca.vn. Say ............................ . + " dislocata (Say) ....................•...... ki s s imm d!nsis Mansfield n. sp ....... , ..... . Conus marylandicus Green ................•....... + + Drillia then Dall ................................. • " aff. D. limatula (Conrad) ...........••...... . . + ' . . . + + I• • J ,: -c + I ; E "' 11 ] ..; 3: ::: ..c u :: .c: :;1 < ... 0 • • ] " " = .j j ' j j 0 p. ;::: Q Q ..: ;;; cii .,; ... ... .,; .D .... .... CO) ... C!> ... 0 ... <XI 0 0 ... ... u: ... ... ... ... + ' + ... + + + + " tuberculata Emmons ............•.. o ••••••• Mangili . A ceriQil. Kurtz & Stimpson ..........• o •••••• Oliva l iteraYl Lamarck ................ . . . . ....... . . . . + + + + + + • I . + I ! .;. I• + + + + Olivella mutica (Say) ......................... . + + " nitidul a Dillwyn ..............•......... . . Marginella n.picinil. Menke ....................... . . " bella (Conrad) ...............•.. , o •••••••• " near M . bella (Con rad)..... . . . . . . . . . . . . . . " contrncta Conrad. . . . . . . . . . . . . . . . . . . . . . . . . . " limatula Conrad.. . . . . . . . . . . . . . . . . . . . + Fasciolarin apicina Dall ....................... . " distans Lamarck ............ . o ••• o • • • • • • • " . t K. + I. ' ' + + + + . , .. I I + . I + + + + . . . I . . . . . . . . + ' + + + + + ' .. ........... + ... .. . ... ... IG• i -" • s • • .; u • u 8 3 • --E p; p; • . I o; • :0 J + + + + + + + + + + + + + + + + + + + 1+ I+ I I + I •I i + + I + + + + + + + + + + + + + + + + + + + + + + + + + + + • I.._. . . . + + . . . + + + + + ? • .. + + . . . + . . . + + + + + REMARKS C l o s e r l o Dup lin form s g1gan en lener ........ . ..... • o • • • • • • • • • • • 1 B . C d . usycon maximum onra var. ? .... o •••••••••••••• .. o < ' ----• ) • ,..____.._.._ ---1 " perversum (Linnaeus ) ................... . . " pyrum ( Dillwyn ).. . . . . . . . . . . . . . . . . . . . . . . . + + • J .. I . . . . + + 1 1 1 . ,,., .I-,._..,_ , . , , . ""''ii: ::JiiiiL :::;::_ = :::;;:-_: , _,.._ ' -.:.::.::: - • - • - • - • - •:;,- • I:.: ... .............. + + + + ---.. . . . . . .. . . . . .. . . . + + + ! 1. • • I Melongena corona Grnelin.. . . . . . . . . . . . . . . . . . . . . . + Ilyanassnlgranifera var. sexdentifem Conrad . . ..... . Ilyanassa isogramma DalJ ........................ . " porcina (Say) var. ? .................... . Alectrion acy.ta (Say) ............................ . " scalaspira (Conrad) ? .................... . " v ibex (Say) ...................... , o ••••• Anachis avara var. trnnslirata Ravenel. ......... . + " obesa C. B. Adams ................... , ... . " " " " var. ? ......... : ..... . . Astyris lunata Say . .............................. . Columbella (Alia ) mntsoni Mansfield n . sp ...... . Murex pomum Gmelin ........................... . Eupleura caudata (Say ) , (poor spec. ) . ............. . " miocenica near var. intermedin Dall ....... . Urosn l p inx near U, perrugatus Conrad ............. . Epitonium delandensis Mansfield ............... ... . + + " aff. E. krebsii MCirch .................. . " " linea tum (Say) ............... , .... . near E. sayann. D a ll ..........•• . . o • • • • • • • •1 TurbonilliL (Pyrgi scus) Sp. B ................. o ••••• • • • + " "Sp.A .......... o ••••• •••••• ••• " (Chemnib;ia) Sp.A ..................... Odostornia (Chrysallida ) Sp. A ........... , , .. , .... . Simnia unipli _qata Sowerby ................ ......... Triforis modesta C . B. Ada.ms ..... , ........ . , ..... Bittium varium Pfeiffe r ........... ...... . o o • • •••••• • • 1 C . h. . .. C B Ad . + ent mps 1 s greenn , . a:ws ....... . . . , ...... ,. Cerithium muscMium Say ... , ..... , ..... • o •••••••• Seila adamsii (II. C. Lea) ....... : ........ o •••••••• • • • • Caecum regu lare Carpenter . .... , ............. , .. , . " near C. carolinian urn DaiJ ..... , . , .. , , . , . . . " putnamens is Mansfie ld n . sp .. , ..... ,,, . . . . " cooperi S . Smith .................... . .... . Turritella burden i Tuomey & Holmes var.?. . . . . . . . . . ? " aff. T. variabilis Conrad ...... .......... , ... 1 . Littorina irrorata (Say) ..................... , ..... + Rissoa geraea Dall ................ , ... , . ,., ... , .. . Risso ina chesnelii Michaud ...... . , ...... , . , .. .. . . . C repidula aculeata Gmelin var. costata.Morton ...... " convexa Say ....... , ........ ... , , . . . . . . . . . . ? " !ornicata (Linne) ........ , . . .. .. . . .. .. . . . + + " p lana say .......... . ............. .......... . N atica pus ilia Say ? ...........•.• o • • • • •••• • o • • • • • • • • + Polyniccs duplicatus (Say) ........... , ... o • • ••••••• • • • Sinum perspectivum Say ................. , , . . .... . Turbo crenuJatus Gmeli n ............... . • . . , .. , .. . Teinostoma near T. reel usa Say .... . . . o • • o o •••••••• Fissuridea alternata Say .......................... . " carolinensis Conrad ......... , .. o • • , ••••• SCAPHOPODA Dentalium near D. attenuatum Say .... 1 " n. ap. ? atf . D. carolin ense Conrad ...... .. + PELECYPODA Nucula proxima Say ............................. . Nucula proxima var. trinuculus Dall ...... o,, ••••••.••. Leda acuta (Conrad) ........... .. , ...... , o •••• •••• Leda trochilia. Dall .....................•... o ••••• . . .;. ..... + •I• • + + . . + ll . :: .;. .. . . . . + + II + .;. 1 .. ... .. ... + ? ? i + + ... tl + Glycymeris pectinatn. Gmelin .... .... o •••• ••••••••• Area limula var . platyura Dall .................... . " " Conrad var. ? .... . . . , ...........•..... +I:!'+ .. " d s . + pon erosa ay ......................... o • •••• I 1 + + + + + + " (Scapharca) campechensis Dillwyn ....... o •• • • • • • • • • • 1 " " A IDII ++ near . campy a a . , ............ " " incongrua Say. . . . . . . . . . . . . . . . . . . . . . . . " " p licatura Conrad. , . . . . . . . . . . . . . . . I ... I ... + + .... + " " IHu + sea anna e prm. , . . . . . . . . . . . . . . " " subsinuata Conrad .................. . " " transversa Say (Light form s) ......... . " " " " (Heavy forms ) ...... + Ostrea equestris Say ............................. . " sculpturata Conrad ..................... ... . ? + " virginica Gmelin ........................... var. Heilprin ..... 1 + g1bbus var. d 1 s locatus Say ................... Plicatura gibbosa Lamarck .. , .................... . " marginat.a Say . ....... . 1 Anomia s implex d'Orbigny..... . . . . . . . . . . . . . . . . . . . . + Crassatellites gibbesii 'l'uoJl!ey & Holmes . ......... . . Crassinella near C. ncuta Dall ... , . ............... . ? + " dupliniana Dall ............. . ..... . . . . " lunulata Conrad ............ , ........ : .. Venericardia perplana. Conrad., ........ , o • • • ••••••• : ! .;. " tridentata Say ......... o ••• , .••••••••• Cardita ara.ta (Conrad) ..... , ............. o ; ••• " ll--:.1--,. ("',.,,.,..,,, I . . . . . . . . . . . . . . . . . . . . . ----------..... , .. , , . , ..... o , •••• • • " congregata Conrad ........... : .....•....... . .:...Codakia. speciosn Roger.s ......................... . Phacoides near P. amiantus Dall ............... ' .. . crenulatus (Coni-a d ) .................... . multilineatus Tuome y & Holmes ......... na.ssulus Conrad var. ? .............•..... " • I + " " radians Conrad .... , .................. . " trisul catus near var . multistriatns Conrad .. + " waccn.mawensis Dnll .................... . + " var. delandensis Mansfield . Divaricella chipolana Dall var. ? .................. . " quad.risulcata (d'Orbigny) .............. Diplod onta acclinis Conrad ... , ..................... -. Sportella protexta Conrad ........ , . . . . . . . . . . . . . . . . . Rochefortin. planulata Stimpson ....... , . . ......... . Cardium isocn.rdia Linmeus .................. o ••••• + . . . I • . .. • I. + . I .. .. I . . • . . . . . , . . I ... I . + r + I ' . + • ... ... + + + : r • + + . I . . + ... + + + " red11lium Dall var ..............•... o ••••• • • • + + " robustum Selander ..................... . + + + t + Dosinia elegan.s Conrad ............... ... o • • • • • • • • ? Transenne lla caloosn.na Dall ............ .... , . . . . . . . . + " stimpsoni Dall ........................ . . Gafrarium metastriatum (Conrad) ................ + 1 Macrocallista nimbosn Selander ....................... + Callocardia sayana (Conrad ) ............•... . ...... Chione cancellata Linnreus ............ o • • • • • • • • • • • + + + " grus (Hol mes) .................• o •••••••••• • • • ; • " latilirata (Conrad) .............•.... . .......... Anomalocardia brasiliana Gmelin ...... • o • • • • • •••••• " caloo sana Dall. . . . . . . . . . . . . . . . . . . . 1 Venus campechiensis Gmelin ........... o • . . o....... + " rileyi Conrad .......................... . tridacnoides Lamarck ? ............. o ••••• • • + + + + + + + + + ' + . . . + + + I + + + + + + + + + + + ... + . . . + + + + + + 1 j • . l + + + + + + ... + + . . . + + + + . I + . . . + . . ' + I. + + + + + + . . . + + + + + . .. + + I + + + + + + + : I • .. ... + + + + + +I + + + • ... + + ... + + + + + + + + + + .. ....... .. ....... + + + + ? . . . . . j Hangc r e fers to spe< i c.., + + + + + + + + + + + + + + + + + , 1 I • 1 .•. , • + + + + + + + + + ............ + . . . I . . . . . . I . . . . . . I + ... I .. I + :J+ ... : + + + + + + + + + + + ' ' ' • I . . • + + + + •• •I • ••• ••. . . .................. + + + + + + ? ...... . .. + .. . .. .... + + ... + + + + . + 1 '-i-" + + + + + + + + + + + + + + + + + + + + + + +!+1:1: + + + + + I I I + I + + I ? + I : 1 . :. . I + Range refers to vnr. l Hmtge refers to spr<:ie s Uange refers to spe c if's -Runge refers to specie.!! Range r efers to species Range refers to spt.o.cies ' + + l .. J+ + + + + + + + + + + + + + + + + + + ... ' + I . I ' + + + + + + + + + + + + + + I• . .. + + . I .. . . . + 1 + . I . I ;. ... + :::I + ? .. . + i'+ t ... . . . . I ... . . . + + I I+ + I I .. + + + I + + .. I ... ... + + I 1 + 1 ? •... + + • I. + ... + + + . .. + + + .;.[• .... + Range refers to the specits 1 1 ? 1 . : . {Like form in Croaton r + 'f ( Pliocene ) of N. C . + + + ... ,. '+ + .. + + + + ... + + + + + I I: I : I : + + + + + + + + + + + Range refers to specic-,o; + + I+ I+ I+ + : .:1:::1 ..... •I• + + + + + + + + + +I" :::::: + + + + + + + . •I•. . . I"" + . . .. . ... . .... . I . . + + ' + + + + + + 1 ? + + + + + +"" + ....... . 1 -... -""'f--... ... ... + . . . . . . . . . . . . . . . ,-: . -:-. .. + + + + . " .......... . + + + .. . .. . ". .. . ... .. .................. . + ' +lr? + . .._. + .;.::: + + . .._. + . .._. + ............ ? + .. . • • 1 I + + + + + J+ . . , . ' . . . + +++++ + + + + + + ;. I.?'!"+ . . ? + + l+ . . . + + ... + . . . I . . . . . . . + ... + + + + + + ... + + + . .... , + : I +I • + I: + + + + + + + + + + 1.+ .;. + + ? + + + + + + + + + + ... + ... + • 1. • !+ : :1 : + + + 1 .1J: + + + + + + + 1 + + + { Oc curs at Cronl;y Hnnge refers t.o spec i es Gemma magnR. Da.ll ......................•....... tri gona. delandensis Mansfi e l d ........•...... + 1 . ::1-+ . . •• + + + + + + + + " purpurea H. C. J..cn .......... . .... •..... " trigona Dall ......................•....... Parastarte triquetra. Conrad ................ , ..... . P e tricola phol ad.iformi s Lamarck .. ,... ... . . ....... . . . . . Tellina d ecli vis Conrad. . . . . . . . . . . . . . • . . • . . . . . . . . . . . . . .. " polita Say ................. . . . . . . . o ••••• •••• • " d . T. propetenera DaU .......•................ " tamprens i s Conra d . ........ . . . ..... . ......... . I Strigilla flexuosa Say. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Semele bellastriat.a Conrad ....... , .. ..., ..... ".!.' ••• •.•• • • • • • " proficua P ou llcu c y ....... . ....... . .... . .--.--;--; .......•. . . . . . .. . . . . . " gibbus " .......•..... ............. Dona.x f osso r Say .......... . , .... . . . • ................ " variabili s Say .......... , . . . . . . . . . . • . . . . . . . . + Lnbi osa ca n aliculata Say ......................... . Ervilia co n centric a G o uld ........................ . Muli n i a congest.a ( Conrad) ..... . . . . ...... ...... .. . Mulinia " n c a r i\I. triquct.ra. Conrad . . . ...... . " contract a ( Conra d ) .......... . . .... . . ..... . . .. + + I + + . .. + + + + " n ea r i\L ca l oosrens i s D all .......... . ....... . late rnli s var. co r bu l o id es Ree ve .... ...... .. . ( h eavy f o r ms ) v ar. A ............. . + I• " " (lo n g f o rm s ) " B ............ . . I + I ? I + " " (rounde d f o rm s ) " C . .....•...... R a n gia cu neat a Gray ...... . .... ...... .... . . . . ... 1 . 1 . . 1 ... 1 .. Co rbul a b arratlian a C . B. Ad a m s . . . . . . . . . . . . . . . . . . . . . + + + ca l oo sre DaU . . . . . . . . . . . . . . . . . . . . . . . . . . . . . + co n l r ac tn Say ................ ... . ..... . . . i nrequa l is Say vnr. A .....• . . . . . 1 ••• ••..•. 1 . . . " " " " n ... . . ........... .. _ ... _I + co stat n L r n nn.rf'k " " :I + + + + + ' . .. + ... + + + + + + + I• + + + ... + ' .. .... " • 1 1 . ... ? + + + + I.:: I ' + + I + + + + + + + + +I+ 1 : ? + + + . I D + I • . I .. ,. + + + : : : ; I . -f . + + + + + + + + + + + + + + + + + + + + + + ' ..... + : .. ... ++ ' . . + + + + I : I. + + ? . . . I , ' + c : + + : I I : . I . . ' ' 1 + . . . . . + + + ' + + + + + +T I+ + + + + 1 ? ? I + + I I 1 I I ? + + . I + + . . I . . . + '.t.• l • + + I • . . . + + I . •' ? 1 + + ... + + + + + ll .. . . .. + + + . . . + . .-c-

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TERTIARY AND QUATERNARY PALEONTOLOGY, NORTHEASTERN FLORIDA 29 5143-Well at Kissimmee, Osceola Co., Fla., depth 96 feet from surface. T. W. Vaughan, col lector. . 5144-From well of Mary Boss , on island in Lake Tohopekaliga, about three miles from Kissimmee, Fla.; depth 150 feet. T. W. Vaughan, collector. 5634-From lower marl stratum at city marl pit about one mile south of DeLand, Volusia Co., Fla. E: H. Sellards, coilector. 5869-From upper marl stratum at city marlpit, about one mile south of DeLand, Volusia Co., . Fla. E. H. Sellards, collector. 6096-6097-Half a mile above A. C. L. R. R. bridge over St. Johns River, Putnam Co., Fla., 5 to 7 ft. below the surface and the same distance above high-water level. F. G. Clapp, collector. 7056-Rose Bluff, Nassau Co., Fla., opposite to and four miles southwest of St. Mary's, Camden Co . , Ga. Otto Veatch, collector. NASHUA MARL , NAME AND ORIGINAL DESCRIPTION The name rriarl was. proposed by G. C. Matson and F. G. Clapp1 who give the following "During the progress of the field work for this report, collections of fossils were obtained which indicate that Pliocene marls are extensively developed in the valley of the St. Johns River, and a of similar marl near Daytona has been referred to the same period. These beds have certain faunal elements vyhich distinguish them from the other Pliocene beds of Flo.rida; and, hence, they are given a distinct name. They are here designated the Nashua marl, from a locality on the St. Johns River, where they are best exposed. Further study may result in uniting al1 of the marine P . liocene of Florida under a single name; but for the present it appears desirable to avoid hasty correlation by the use of local names for th. e beds of different localities, especially where conditions governing deposition appear to have been unlike. ((Stratigraphic Position:-The Nashua marl is thought to rest unconformably ,upon the at DeLand; but this opinion lacks con firmation, as the collections from that locality have not be 'en studied in sufficient detail to determine the exact age of the beds. At various localities, the contact between this formation and the overlying Plei s to cene sand has observed and it i s everywhere n 1arked b y a distinct unconformity. The Pleistocene beds rest upon an undulating surface of the Nashua marl, which is clearly due to erosion, and the contrast !Matson; G. C., and Clapp, F. G. A preliminary report of the geology O>f Florida with special reference to the stratigraphy. Fla. State Geol. Survey, 2nd Ann. Report, pp. 128-130, 1909. 

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30 GEOLOGICAL SURVEY-15TH ANNUAL REPORT between the fossiliferous marl and the overlying barren sands helps to emphasize the break between the two. "Lithologic Character:-The Nashua marl bears a strong lithologic resemblance to the Caloosahatchee marL There is the s ame alternation of sand beds with shell marl. The matrix of the Nashua marl, while usually calcareous, is always more or less sandy and sometimes consists of nearly pute sand. The shells are commonly well though locally a marl consisting of broken and eroded fragments of shells is not uncommon. However, the organic remains are so well preserved that it is easy to obtain gooq collections of from this formation. uThickness:-The Nashua marl is much thinner than the Miocene strata. This fact, together with its distribution beneath the lowlands near the coast, indicates that the Pliocene submergence was less . extensive than the Miocene; and the presence of shallo . w-water fossils shows that the Pliocene sea did not attain any great depth over that part of the State w here the marinebeds are now exposed. The N ashua marl is dom more than six or eight feet thick, but it attains a .greater thickness. A series of samples of sand and marl from a at DeLand indicates that at that locality this marl has a thickness of about thirtytwo feet. uPhysiographic Expression:The, Nashua marl occupies the St. Johns Valley, where it underlies a broad terrace bordering stream. It probably occurs beneath the plain east of St. Johns River, but the overlying Pleistocene forms such a thick mantle that the Nashua marl has no influence on the topography. On the whole, this formation has little or no influence on the topography of the State. . . uPaleontolo gic ChMacter :-'l'he fauna of the N{ashua tnarl is only imperfectly known, but it has been sufficiently studied to show that it resembles that of th . e Caloosahatchee marl. .. most striking difference between the faunas of the two formations is th e existence of certain species in the Nashua marl which occur in the 'Waccamaw' fauna of the Carolinas, but are not to be present in the Caloosa . hatchee tnarl. This affinity with the fauna to the north suggests the existence of a cold current along the Atlantic coast which permitted a southward migra tion of the 'Waccamaw' fauna . . The lack of exposures in the south central portion of the peninsula prevents the tracing the connection 

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TERTIARY AND QUATERNARY PALEONTOLOGY, NORTHEASTERN FLORIDA JI betw'een the two formations and the detennination of the limits of the southward migration of the species from the 'Waccamaw' fauna. ({Structure :-.The Nashua marl is exposed at only a few localities in the St. Johns Valley an9 it is difficult to forn1 any definite ide:1 concet:ning its structure. It has probably been subjected to the same defonnation as the Caloosahatchee marl, but the isolated exposures afford no oppor tunity to observe evidences of folding. The dip is doubtless seaward and it is probably very slight. ({Local Details:-ln the St. Johns Valley there are a number of exposures of the Pliocene marl which have been designated the Nashua n1arl. At the type locality, one-fourth tnile south of Nas hua, Putnan1 County, there is an exposure of five feet of '"' hite sand , resting unconformably upon about fifteen feet of white shell marl. " LISTS OF SPECIES FROM THE NASHUA MARL 4865.-A quarter of a mile . south. of Putnam Co., Fla. (Type locality of the Nashua n1arl). (See Matson, . G. C., and Clapp, F. G., Fla. Geol. Survey, 2nd Ann. Rep't p. 130, 1909.) . Approved or Changed. Terebra protexta (Conrad), not found. Terebra dislocata (Say). Terebra concava (S'ay), var. ( ?) . Conus marylandicus Green. O liva literata Lam'k. Olivella mutica (Say). Marginella limatula Conrad. Marginella cf. M. floridana Dall. Busycon maximum Conrad ( ?) (yo.). Eupleura miocenica, var. near intermedia Dall. U rosalpinx, near perrugatus Conrad. Ilyanassa porcina (Say), var. ( ?) Ilyanassa isogramma Dall ( ?) I lyanassa gran.ifera, var. sexdentata Conrad. Ilyanassa porcina (Say), var. Anachis avara, var. translirata Ravenel. Turbonilla. ' Eulima. Cerithiopsis greeni C. B. Ads. Crucibulum cf. C. auricula Gmelin (yo.). Crepidula convexa Say, ( ?) (yo.). Natica pusilla Say ( ?). Littorina irrorata (Say). . Dentalium, near D. carolinense Conrad. Area (Nretia) limula, var. platyura Dall. Original. Terebra protexta Conrad. Terebra dislocata Say. Terebra concava Say. Conus marylandicus Green. Oliva literata Lamk. Olivella mutica Sa ' y. Marginella pardalis Dall. Volutella amiantula Dall. Fulgur maximum Conrad. Eupleura miocenica var. intermedia Dall. Murex pomum Linn. Ilyanassa porcina Say. Ilyanassa isogramma Dall. Ilyanassa granifera Conrad. N ass a scalaspira Dall. Anachis avara var. calooscensis Dall. Turbonilla. Eulima. Cerithiopsis greeni C. B. Ads. Crucibulum auricula Gmelin. Crepidula convexa Say. . N atica ( Cryptonatica) pusilla Say. Littorina irrora ta Say. Dentalium carolinense Conrad. Area (Nretia) limula, var. platyura Dall. 

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32 FLORIDA GEOLOGICAL SURVEY-15TH ANNUAL REPORT Area, near A. campyla Daii. Ostrea virginica Gmelin. Pecten eboreus, var. solaroides Heilprin. Anomia simplex Orbigny. Crassinella lunulata Conrad. Crassinella dupliniana Dall. Phacoides waccamawensis Dall. Phacoides multilineatus T. and H. Divaricella chipolana Dall, var . ( ?) Area scalarina Heilprin. Venus tridacnoi'des Lamarck. ( ?) Dosinia elegans Conrad. cancellata Linne, not found. Gemma magna Dall. Gafrarium metastriatum (Conrad). . Mulinia, near M. caloosrensis Dall. Mulinia, near M. triquetra Conrad. Corbula barrattiana C. B. Ads. Area campyla Dall. Ostrea virginica Gmelin. Pecten madisonius Say. Anomia simplex Orb. Crassine11a lunulata Conrad. Crassinella acuta Dall. Phacoides tuomeyi Daii. Phacoid e s multilineatus T. and H. Davircella chipolana Dall, var. ? Cardium robustum Sol. Venus tridacnoides Lam. Dosinia, young-D. elegans Conrad? Chi one cancellata Linn. Gemma magna Dall. Pitaria ( ?) Young. Mulinia congesta Conrad. Mulinia cong esta var. triquetra Conrad. Corbula cuneata Say. Species not originally listed from this station : Crepidula fornicata (Linne). Ostrea sculpturata Conrad ( ?) (young). Phacoides trisulcatus near var. multistriatus Conrad. Corbula inrequalis Say, var. B. Geologic horizon originally reported : Pliocene. Geologic horizon believed to be in this report : Pliocene. 5010.-Half a mile south of DeLeon Springs station, Volusia Co., Fla. Eleven to s eventeen feet below the surface (see Matson, G. C., and Clapp, F. G., 2nd Ann. Rep't Fla. Geol. Survey, 1909, p . 132.) Approved or Changed. Margin ell a co.ntracta Conrad. Terebra dislocata (Say) ( ? ) (yo.). Oliva literata Lamarck. Melongena corona Gmelin (?) (yo.) . Crepidula convexa Say. Crepidula aculeata Gmel. Crepidula plana Say. Cryptonatica pusilla Say ( ?) Area transversa Say. Area limula, var. platyura Dall. Area limula, var. platyura Dall. Area plicatura Conrad. Pecten gibbus Linne. Carditamera arata Conrad. Venericardia tridentata Say. Phacoides multilineatus Tuomey and Holmes. Phacoides waccamawensis , delandensis Mansfield. Phacoides radians Conrad. Cardium robustum Solander. Original. Marginella contracta Conr-ad. Terebra dislocata Say. Oliva literata Lam. Melongena corona Gmel. Crepidula convexa Say. Crepidula aculeata Gmel. Crepidula plana Say. Cryptonatica pusilla Say. Area transversa Say. Area ponderosa Say. Area Iimul a, , var. platyura Dall. Area plicatura Say. Pecten gibbus Linn. Carditamera arata Conrad. Venericardia tridentata Say. Phacoides multilineatus T. and H. Phacoides waccamaensis Dan. Piiacoides radians Conrad. Cardium robustum Solander. 

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TERTIARY AND QUATERNARY PALEONTOLOGY, NORTHEASTERN FLORIDA 33 Cardium isocardia Linne. Venus rileyi Conrad. Chione cancellata Linne. Mulinia lateralis Say. Corbula inrequalis Say ( 2 vars.). Cardium isocardia Linn. Venus campechiensis Gmel. Chione cancellata Linn. Mulinia lateralis Say. CoThula inrequalis Say. Other species not originally reported from this station are: Mangilia cerina Kurtz and Stimpson. Olivella mutica (Say). Marginella, near M. bella (Conrad). Crepidula fornicata (Linne). Rochefortia planulata Stimpson. Gemma Dall. (?) Mulinia contracta ,(Conrad). Geologic horizon originally reported: . Pliocene. Geolqgic horizon in this report: (Nashua marl). The following species are cited from DeLeon Springs with assigned age by Dr. Wm. H. Dall, in the _ Transactions of the Wagner Free Insti tute of Science of Philadelphia, Vol. III: Crepidula Gmel. J (p. 357) ; Pliocene. l (p. 1597) ; Miocene. Ilyanassa isogramma Dall, (p. _ 239) ; Pliocene ( ?) Littorina irrorata Say, ( p. 320) ; Pliocene . . Carditamera arata Coorad, (p. 1414); Pliocene. Carditamera arata Conrad, (p. 1597) ; Miocene. Chama congregata Conrad, (p. 1400) ; Miocene. Echinochama arcinella Linne, (p. 1597) ; Miocene. Echinochama arcinella Linne, (p. 1612) ; Pliocene. 5019.-0ne-fourth of a mile south of the railroad station at Orange City, Fla., basal member. (See Matson, G. and Clapp, F. G., Fla. Geol. Survey, 2nd Ann. Rep't, p. 149, 1909. ) . Approved or Changed. Iineatus Say, var. Terebra concava (Say), not found. Olivella nitidula Dillwyn. Oliva literata Lamarck. Busycon maximum var. (yo.). Litorina irrortata (Say). Leda acuta (Conrad), var.' Area transversa Say. Original. Melampus lineatus Say. Terebra concava Say. Olivella mutica Say. Oliva literata Lam. Fulgur pyriformis Conrad. Littorina irrorata Say. Leda acuta Conrad. Area transversa Say. Other species from this station not listed with the above are: Crassinella lunuiata Conrad. Venericardia tridentata S _ ay. Cardita arata (Conrad). Phacoides multilineatus Tuomey and Holmes. 

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34 FLORIDA GEOLOGICAL SURVEY-15TH ANNUAL REPORT Phacoides waccamawensis delandensis Mansfield . Gafrarium metastriatum (Conrad). Gemma trigorlia de _I aridensis Mansfield. Mulini a lateralis Say, (2 vars.) Corbula inrequalis Say, {2 vars. ) • Geologic horizon given with the original list: Pleistocene ( ?) Geolog i c horizon believed to be in this report: Pliocene (Nashua marl) . . . . Following is a list of fossils collected by Mr. F. G. Clapp from onemile nort h of the railroad s tation , Qrange City, Fla. S.ta. No. 5011: Terebra concava ( Oliva literata Lam. var. ( ?) Area transversa Say ( ? ) Ostrea virginica Gmelin. Venericardia perplana Conrad. Venericardia tridentaia Say . Venus rileyi Conrad. Gemma trigona delandensis Mansfield. Mulinia lateralis Say. Geologic horiz<?n : Pliocene (Nashua marl) . Sta. No. 5869 (No.3 of section) and 5634 (No.1 of section). Marl pit about one mile south of DeLand, Vol usia Co., Fla. (For original list of species see Mansfield, W. C., Fla. State Geol. Survey, 11th Ann. Rep't, . . pp. 113-115, 1918.) \ Geologic horizon : Pliocene (Nashua marl) . . . AGE OF THE NASHUA MARL The fossils from the type of the Nashua marl were identified by Dr. T. W. Vaughan, who makes the following statement1 in referring to the geolog i c age: "Pliocene, [ t hough] the presence of Pet;ten madisonius suggests the presence Mioce _ :e in the same bluff. The fauna has an additional intere st in containing speci e s found in the 'Waccam3;w beds' but not in the . Caloosahatchee." The present writer believes this P ecie n i s P. var. solaroides Heilprin , a Pliocene variety found in the Caloosahatchee marl. Another form is listed, Mulinia congesta (Conrad), which is believed to be closely allied to M. caloosa e nsis Dall. Even granting that. this variable species (Mulinia lFia. State Geol. Survey, 2nd. Ann. Rep't, p. 130, 1909. 

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TERTIARY AND QUATERNARY PALEONTOLOGY, NORTHEASTERN FLORIDA 35 congesta) occurs in the N as'hua marl, its presence has been reported from the Croatan beds of North Carolina. The close relations hip of the fauna of the . Nashua marl at its . type locality to that of the Waccamaw is on the correlation sheet. When 28 of the better preserved forms from the Nashua marl are com pared with other faunas, about 75 per cent occur in the Caloosahatchee, and 57 per cent are represented in the Recent fauna. None are found to be exclusively Miocene and five appear to be confined to the Pliocene. The following three appear to be diagnostic Pliocene species,-Arca li mula var. platyura Dall, Area scalarina Heilprin, and Phacoides wacca1nawensis DalL The conclusion deduced from the foregoing facts place s the Nashua marl at its type localit y in the Pliocene, appar ently the basal Pliocene, and stratigraphicall y equivalent to the beds referred to the Waccamaw inarl in the Carolinas. It is believed by the writer, relying upon data at hand, that no faunas considered in this paper, excepting those in deep wells at or near Kissimmee, are older than the Pliocene, and if the Miocene is present in this area, it is found only in well borings. This belief is founded not only upon the facies of the fauna, but upon the absence of diagnostic Miocene species such as occur in known upper Miocene deposits of the sou thea ste rn United States. The following five will be cited followed by these indices of their occurrence: A . Alum Bluff, Fla.-upper bed. C. Coe's Mill, Fla. D. Natural Well, or Duplin of N.C. M . Duplin a t Mayesvi lle, S. C. ] . Jackson Bluff, Fla. T. Tallahassee, Fla. (16 mi. S. W.) A rca scalaris Conrad, A. C. D. M. Phacoides tuom eyi Dall, C. D. M. J. T. (Reported in the Pliocene at Walker's Bluff and Neill's Eddy Landing, N . C.) Dentalium attenuatum Say, A. D . J. M. Ecphor.a quadricostata Say, A. D. M. Turritella variabilis Conrad, A. J. M. T. Of these species, none are found with certainty among the fauna referred to the Nashua marl. MIOCENE AT KISSIMMEE The following is a new list of fossils said to have been taken 'between depths of 65 and 100 feet in a well at Kissimmee, Osceola Co., Fla., C. 0 . Newlands, driller. Station 5016: 

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3 6 FLORIDA GEOLOGICAL SURVEY-I 5TH ANNUAL REPORT Terebra dislocata (Say). Terebra (Acus) kissimmeensis n. sp . Drillia aff . D. Iimatula (Conrad). O liva literata Lamarck. O livella mutica (Say). Marginella apicina Menke, var. A l ectrion scalaspira (Conrad) ( ?) • Co lumb e ll a (Alia) Matsoni, n. sp. Turritell a burdeni T . and H., var. ( ?) Turritella aff. T. variabili s Conrad, ( ?) (yo .). Crepidula fornicata ( Linne ) . Crepidula plana Say. Polyn ices duplicatus (Say). Dentalium, near D. attenuatuni Say. Led a acuta (Conrad). . Area transversa Say ( ?) (frag.). Cardita n. sp. Phacoides crenulatus (Conrad). Phacoides, near var. multistriatus Conrad. Diplodonta acclinis Conrad. Mulinia congesta (Conrad). .. Geologic horizon: Miocene and probably also some post-Miocene. The presence of the species Drillia aff. D. limatula, burden,i var. ( ?) , Dentalium, near D . atte11,uatum, and M congesta (Conrad) (heavy forms) ind i cate Miocene age . 5144.-Fossil s obtained at a depth of 150 feet in the well of Mary Boss, on an island in Lake Tohopekali ga, about 3 miles from Kissim mee, Florida. ( 1 See Matson, G. C., and Clapp, F. G . , Fla. State Geol. Survey, 2nd Ann. Rep't, p. 133, 1909.) Revised List. Acteocina canaliculata (Say). Olivella mutica (Say). Marginella (fragment). Epitonium aff. E. Jineatum (Say) (yo.). Turritella subannulata H e ilprin ( ?) (yo.). TurriteJla burdeni T. and H. ( ?) C-\uc ibulum auricula Gmelin ( ?) (yo.) . Dental ium, near D. attenuatum Say. Cadulus quadridentatus Dall ( ?) Nucula proxima Say. Leda trochilia Dall. Pecten gibbus Linne ( ?) (frag.). Anomi a simplex Orbigny. Venericardia tridentata Say ( ?) (yo.). Phacoides multilineatus T. and H. ( ?) Callocardia sayana (Conrad) (?) (yo . ) . Chione cancellata L. ( ?) (yo.) . Original List. Tornatin a canaliculata Say. Olivella mutica Say. Marginella fragment. Scala lineata Say. Turritella subannulata Hpn. Turritella apicalis Hpn. Crudbulum auricula Gmel. Dentalium caloosc.ense Dall. Cadulus quadridentatus Dall (?) Nucula proxima Say. Leda n. s p., also Pliocene of Shell Creek.' Pecten gibbus Linn. Anomia simplex Orb. Venericardia tridentata Say. Phacoides, worn spec im ens . Callocardia sayana Conrad. Chione cancellata Linn. 

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TERTIARY AND QUATERNARY PALEONTOLOGY, NORTHEASTERN FLORIDA 37 Gemma trigona Dall. Gemma magna Dall. Parastarte triquetra -Conrad, not found . En sis (fragment). Mulinia lateralis Say, var. earbuloides Reeve ( ?) Balanus sp. Gemma trigona Dall. Gemma sp. Parastarte triquetra Conrad. Ensis , fragment. Mulinia lateralis Say. Balanus . sp. Geologic horizon given in the original report : Pliocene. Geologic horizon believed to be in thi s report: Probably Miocene, including some Pliocene. The presence of the species D e ntal i um, near D . . atte n uatum, Led a t r och i l i a , and Tu1'r i t e lla burd eni ( ?) sugg e s t Miocene. L eda troch i tia is common in the Miocene. There are in the National Museum collection, three or four specimens from the Caloosahatchee Pliocene very near L eda troch ilia, but Led(]) act tta is the most comman species there. LATE PLIOCENE OR EARLY PLEISTOCENE DEPOSITS 5009.-East side St. Johns River, seven miles below the railroad bridge near Sanford, Fla. (See Matson, G. C., and Clapp, F. G., 2nd Ann. Rep't Fla. Geol. Survey, 1909; p. 133 . ) Approved or Changed. Area, near A . camp yla Dall. Crassinella lunulata Conrad. Phacoides multilineatus T. and H. Chione cancellata Linne . -Transenella caloosana Dall. Anomalocardia caloosana Dall. Semele profieua Poulteney ( ?) Abra requalis Say. Corbula barrattiana C. B. Adams. Original. Area campyla Dall .. Cra!sinella lunulata Conrad. Phaeo ides multilineatus T. and H. Chione cancell ata Linn. Transennella eaioosana Dall. Anomalocardia caloosana Dall. Semele. Abra requalis Say . Corbula contracta Say. Other species from this station not originally reported with the abo:ve list are : Led a acuta (Conrad). Tellina polita Say. Tellina cf. T. propetenera Dall. Mulinia lateralis var. Reeve. Geologic horizon given in original report: Probably Geologic horizon believed to be in this report: uppermost Pliocene ' or lowest Pleistocene. A rca campyla appears to be confined to the Pliocene. The form in this collection is nearer to this species although not typical. 

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38 FLORIDA GEOLOGIC A L SURVEY-15TH ANNUAL REPORT 5008.--.,;Eas t side of the St. Johns River, five miles below the Sanford railro ad bridge. (See Matson, G. C., and Clapp, F. G., 2nd Ann. Rep't of Fla. Geol. Survey, 1909; p. 132 . ) Approved or Changed. Acteocina canaliculata (Say). Olive II a mutica (Say). Busycon pyrum (Dillwyn). Busycon perversum (Linne) . Not found. Alectrion v ib ex (Say). Crepidula fornicata Say ( ?) (yo.). Nucu la proxima Say. Area, near A. campyla Dall. Mytilus venustus Linne. Phaco id es multilineatus T. and H. Cardium redalium Dali (not typical, ap-proaching C. muricatum Linne. Lrevicardium mortoni Conrad ( ?) Anomalocardia caloosana Daii ( ?) (young). Venus campechiensis Gmel. Chione cancellata Linne. Tellina declivis Conrad. Corbula barrattiana C. B. Ad's. ,, Mulinia Iateralis, var. corbuloides Rve. Pholas costata Lamarck. Original. Tornatina canalicurata Say. Olivella mutica Say. Fulgur pyrum Dillwyn. Fulgur perversum Linne. N assa elevata Say. Nassa vibex Say. Crepidula fornicata Say. Nucula proxima Say. Area transversa Say. Mytilus venustus Linn. Phacoides multilineatus T. and H. Cardium redalium Dall. Lrevicardium serratum Linn. Anomalocardia caloosana Dall. Venus campechiensis Gmel. Chione cancellata Linn. Tellina declivis Conrad. Corbula contracta Say. Mulinia lateralis Say. Pholas costata Lam. Other species from this station not originally reported in above list are: Alectrion acuta (Say). This may be the same form as listed as N ass a el etzJata Say. Venericardia tridentata Say. Parastarte triquetra Conrad. Donax variabilis Say. Gemma purpurea H. C. Lea. Geologic horizon given with the original report: "Probably Pliocene ." Geologic horizon believed to be in this report: Upper Pliocene ot lowest Pleistocene. The two species, D oooz variabilis and Gemma purpurea, as noted, were not listed in the original report. The two species appear to be exclusively post-Pliocene. If they came from the sa me s tratum as the other listed species, the age would indicate postPliocene rather than Pliocene. 486 ,6.-Half a mile above A. C. L. R. R . Bridge over St. Johns River, Putnam Co., Fla. Vertical cliff three to eight feet above high water level. (See Matson, G. C . , and Clapp, F. G., 2nd Ann. Rep't Fla. Geol. Survey, 1909; p. 131.) 

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TERTIARY AND Q.UATERNARY PALEONTOLOGY, NORTHEASTERN FLORIDA 39 Approved or Changed. Acteocina canalicul ata (Say). Uro salpinx, near U. perrugatus (Conrad). Astyris lunata Say. A:nachis obesa (C. B. Ads.). Anachis obesa (C. B. Ads.). Epitonium, near E. sayana (DaB). Crepidula convexa Say ( ?) (yo.). Rissoina chesnelii (Michaud). Area, near A. campyla Dall. Ostrea sculpturata Conrad ( ?) (yo.). Modiolus. Crassinella lunulata Conrad. Carditamera arata Conrad ( ?) (yo.). Phacoides multilineatus T. and H . not found. Original. Tornatina canaliculata Say. Urosalpinx perrugatus Conrad. Astyris lunata Say. Anachis. Anachis. Scala. Crepidula convexa Say. Rissoina chesneli Mich. Area campyla Dall. Ostrea. Modiolus. Crassinella lunulata Conrad. Carditamera arata Conrad. Phacoides multilineatus T. and H. Lucina. Lucina. Cardium redalium Dall, var. (not typical), Cardium redalium Dall. near C. muricatum Lin(}. Cardium robustum Solander. Chione cancellata Linn. Dosinia elegans Conrad. Macroca lli sta nimbosa s olander. Semele proficua Poulteney ( ?} Mulinia lateralis Say. Corbula barrattiana C. B. Adams. Corbula contracta Say, (not originally reported). Anomia simplex d'Orb., (not originally reported). Cardium robustum S'ol. Chione cancellata Linn . Dosinia elegans Conrad. Macrocallista nimbosa Sol. Semele purpurea Gmel. ? Mulinia lateralis Say ? yo. Corbula cuneata Say. Geologic horizon originally reported: Pliocene. Geologic h or izon believed to be in thi s report: Uppermost Pliocene or early Pleistocene. A 1'"CCD} ne a r A . ca1npy l a and Carditt, 1 n va r. a nd Ostrea sculpturata ( ?) strongly indicate Pliocene age rather than later. 6096-7.-I-Ialf a mile above the A. C. L. R. bridge over St. Johns River, Putnam Co., Fla., five to seven feet below surface and 5 to 7 ft. above high-water level. F. G. Clapp, collector. This lot is appa rently frotn the sa me locali ty as station 48GG, but contains species not originally reported from there: Acteocina canaliculata (Say). Alectrion acuta (Say). Anachis obesa (C. B. Ads.). Astyris lunata Say. Turbonilla (Pyrgiscus) sp. A. Odostomia ( Chrysallida) sp. A. Triforis mod esta C. B. Ads. Cerithiopsis greenii C. B. Ads. S'eila adamsii (H. C. Lea). Crecum regulare Carpenter. 

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40 FLORIDA GEOLOGICAL SURVEY-15TH ANNUAL REPORT Ca!cum, near C. carolinianum Dall. Ca!cum putnamensis n. sp. Crecum cooperf Smith. Risso a gera!a . Dall. Rissoina . chesnelii (Mich.). Crepidula fornicata (Linne). Crepidula plana Say. . Teinostoma, near T. reclusa Say. Nucula proxima Say. Area limula, var. platyura DaB ( ? ) Area transversa Say, (light form). Anomia . simplex Orbigny. Crassinella lunulata Conrad. Cardita floridana Conrad. Phacoides multilineatus T. and H. Sportella protexta Conrad. ,. Dosinia elegans Conrad. Chione cancellata ' Linne. Tellina polita Say. Semele proficula Poulteney. Abra a!qualis Say. . Tagelus divisus Spengler. Mulinia lateralis Say, var. B. Corbula barrattianna C. B. Ads. Corbula contracta Say. Geologic horizon : . Uppermost Pliocene or lowest Pleistocene. PLEISTOCENE DEPOSITS COMMENTS ON FAUNAS FROM FORMERLY LOCALITIES 7056.-Rose Bluff, N ' assau Co., Florida. Opposite to and 4 miles west of St. Mary's, Camden Co., Ga. (See { Ga. Geol. Surv. Bull. No. 26, p. 436, 1911, for fossil list). Geologic horizon given in original report: Pleistocene. Geologic horizon believed to : be in this report : Pleistocene. The fauna at this locality is related to that at station 5869 (DeLand, stratum No. 3 of section) as approximately 50 per cent of the Rose Bluff species are represented in that stratum; but the Rose Bluff contains certain species, as Area incongrua} . Ervilia concentrica} and probably Donaz variabilis} that appear to. occur ovly in deposits of postPliocene age. 5143.-Well at Kissimmee, Osceola Co., Fla.; depth 96 ft. from surface. (See Matson, G. C., and Clapp, F. G., 2nd Ann. Rep't Geol. Surv., 1909, pp . 149-150 for list.) Geologic Horizon given in original report: Pleistocene. Geologic Horizon believed to be in this report: Pleistocene. 

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TERTIARY AND PALEONTOLOGY, NORTHEASTERN FLORIDA 41 Two species from . this locality, Ostrea equestris Say, and Donax variabilis Say, are believed to be exclusively post-Pliocene and Recent. 5003.-In a ditch 4 miles west of Eau Gallie. (See Matson, G. C., .and Clapp, F. G., 2nd Ann. Rep't Fla. Geol. Surv., 1909, p. 151 for list. Geologic horizon given in original report: Pleistocene. Geologic horizon believed to be in this report : Pleistocene. Fou! species, Petri,cola . Lam., D onax variabilis Say, Drllia thea Dall, and Transennella stimpsoni Dall reported T. caloosana Dall-are believed to be exclusively postPliocen e. Two Area limula var. platyura Dall (one valve), and Corbula caloosae Dall (one valve) appear to be exclusively Pliocene. 4837.-Two miles southeast of -Eau Gallie, on peninstila south of point of Mer.ritt's Island. (See Matson, G. C., and Clapp, F. G., 2nd Ann. Rep't of Fla. Geol. Survey, 1909 . , p. 151, for list of fossils.) Geologic horizon given in original report : Pleistocene: Geologic horizon believed to . be in this report: Late Pleistocene. All species are represented in the recent fauna and one species, Donax variabilis Say, appears to be exclusively post-Pliocene and Recent. NEW LISTS OF' SPECIES FROM TWO LOCALITIES miles west of Titusville, Brevard Co., Fla.: Glycymeris pectinata Gmel. ( ?) (yo.). Venericardia tridentata Say. Codakia speciosa Rogers. Phacoides multilineatus T. and H. Donax yariabilis Say.' Mulinia lateralis Say. Geologic horizon : Pleistocene. The larger part of the collection consists of Donax variabilis Say. 5017.-Near Michaels marlpit, one mile south of point, Daytona, Volusia Co., Fla., collected by G. C. Matson, Acteocina canaliculata (.Say). Olivella mutica (Say). Alectrion acuta (Say). Odostomia (Chrysallida) sp. A. Bittium varium Pfeiffer. 

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42 FLORIDA GEOLOGICAL SURVEY-15TH ANNUAL REPORT Cerithium musearum Say ( ?) Crepidula plana Say. Crepidula fornieata (Linne). Nueula proxima Say. Area ponderosa Say . Area eampeehensis Dillwyn. Area subsinuata Conrad. Area transversa Say ( 2 forms). Ostrea virginiea Gmelin. Plieatula gibbosa Lamarck. Anomia Orbigny. Venerieardia perplana Conrad. Venericardia tridentata Say. Chione caneellata Linne. Chione grus (Holmes). Anomaloeardia caloosana Dall. Venus campeehiensis Gmelin. Gemma purpurea H. C. Lea. Parastarte triquetra Conrad. Tellina tamprensis Conrad. Semele bellastriata Conrad ( ?) A bra requalis Say ( ? ) Tagelus divisus Spengler. Donax variabilis Say. Mulinia lateralis, var. eorbuloides Reeve. Mulinia lateralis, vars. A. and B. Rangia cuneat? Gray. Geologic horizon : Pleistocene. Three species, A1ca campechensis billw., Ge1nma purpurea H. C. Lea, and Don -ax variab-ilis, appear to be exclusively post-Pliocene. Area subsinttata Conrad, hitherto, has been reported only from P liocen e o f the Croatan beds, near New B ern, Craven Co., N. C. \ 

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-TERTIARY AND QUATERNARY PALEONTOLOGY, NORTHEASTERN FLORIDA 43 EXPLANATION OF CORRELATION TADLE In the correlation table given below, the statio n numbers arranged along the l e ft-hand margin have no to the age relation of the contained faunas. In some cases n o t all the forms from t he locality are con s idered in the tin1e-range, as the omitted ones are too poorly preserved for s pecific identification. The per centag e of the fauna fron1 each l oca l ity that is believed to exist in the recent fauna is al so given. These percentages are not entire l y u sed as a basis for tin1e correlati o n , as in s ome ca s e s th e number of species from a l ocality is small and t he percentage may not expre ss CORRELATION TABLE 'i >. Qi ., .... 1:: > en .... s= c.J >. >. en 8 0 =' 1:: Qi -.... c.J > 8J c.J ll-4 > .... .... 0 -en en .... . ... =' =' (,! L 8. ll-4 c.J c.J -..c:: 1-< X cn c.J 1:: .... ... 0 aS aS L L c.J ..c:: 0 ... s aS c.J .... s= s= .8 1:: 1: aS en c.J 0 1:: c.J c.J en c.J c.J 0 c.J 0 ] 0 0 aS c; c.J 0 en .... .... i .... 0 z ll-4 Q ll-4 ll-4 -------4837, 2 mi. S. R. Ea.u . ............. 0 4 ,_ 4 9 f l 0 0 1 " I I 4865, Nashua. mi. S. Type L oc ........ 1 b 2t 21 1 6 1 6 0 .5 0 4866, 72 mi. above A. C. L. R. R. bridg e .. 1-t (j 1 1 1 2 r;:s 1 3 0 ' ? 5003 , 4 mi. \V. of Eau Gallil! ..... ........ 3U ];) 22 31 3[, 33 0 2 4 5008, 5 mi. b e l ow Sanf ord R. R. bridge .... 1 k 0 1 6 12 1.j 1 7 17 0 ' 2 . 5009, 7 mi. b e l ow Sanford R. R. bridg e .... 11 6 tl 11 11 ( t 0 0 0 I . 5010, 72 mi. S. D e L eon Springs ........... 21 1 6 20 H i 17 1tJ 1 4 ? 1 0 5010, and oth e r coiiec li o n s from DeLeon ... ;jj 2 3 30 2:") 2 3 2P 20 ' 2 0 I 5011, Y2 mi. N. Orange City R. R . Sta .... ('; 5 6 li (j 5 v 0 0 0 5012, 7 mi. \\'. of Titusvill e . ............. 4 n 3 2 3 4 <:I 0 0 1 .) f) 5016, W e li, Kissimmee .................. 12 11 1 0 ]() g 8 b ? 0 0 5017, Daytona ......................... 2 7 12 2 ' ... l(j 21 2 6 2 5 0 1 3 ., 501 9, U mi. S. o r Orange City R. H.. Sta .. . 11 11 1 0 1 0 b ,... () ? 0 I ... 5143, \Vdl, Kis s imm ee ........... . . . . ... H l 1 0 1 5 f) 13 1 8 16 0 0 2 5144, Well, on i s land, L. T ohopeka liga. .... 7 ,... 6 (i 6 4 4 ? 0 0 I 5634, D eLand, l ower bed ............... . 1 2 11 11 l J 9 1 0 9 ? 0 0 5869, DeLand, uppe r bed ................ 4 5 34 42 37 2rl 2 9 ' 3 2 . 6096-7, Vz mi. above A. C. L . R . R. L r i dgc .. 2 7 1 4 2 : 2 2fi 2ti 0 0 0 70.36, Rose lll uff ........................ 12 1 4 t: J 12 I:-: 1 7 0 0 2 ' gJ .... en 1:: (,! '"' .... 0 tl() .s 1: c.J ... ll-4 100 5 7 93 85 94 82 67 65 83 75 67 93 55 8 4 57 75 64 96 94 

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FLORIDA GEOLOGICAL SURVEY-15TH ANNUAL REPORT the true condition. In other cases . where the fauna is cosmopolitan and the number of species large, the percentages are believed to be helpful. LitST OF STATIONS WITH A GE ASSIGNM ENTS Pleistocene Late Pliocene or tocene early PleisPliocene, (Nashua marl) Probably Miocene including} some Pliocene Miocene, probably including} post-Miocene [ 4837 (2 mi. S. E. of Eau Gallie) (late). 5017 (Daytona). 5012 (Titusville, 7 mi. W.). 5003 (Eau Gallie, 4 mi. W.). 5143 (Well, 96 ft. K.issi . mmee) . 7056 (Rose Bluff). 4866 ( 0 mi. above A. C. L. R. R. bridge). 6096-7 ( 0 mL above A. C. R. R. bridge). 5008 ( 5 mi. below Sanford R : R. bridge). 5009 ( 7 mi. below Sanford R. R. bridge). 5011 (% mi. north of Orange City R. R. Sta.). 5019 mi. south of Orange City R. R. Sta.). 5869 (Upper bed at DeLand). 5634 (Lower bed at DeLand). 4865 (Nashua, type locality). 5010 (DeLeon Springs). 5144 (WeB on island in Lake Tohopekaliga). 5016 (Well, 65 to 100ft., Kissimmee). • 

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TERTIARY AND QUATERNARY PALEONTOLOGY, NORTHEASTERN FLORIDA 45 DESCRIPTION'S OF NEW SPECIES TEREBRA (ACUS) KISSIMMEENSIS N. SP. Plate I, Figures 9 and 10 Shell solid, polished, attenuated, conical with about 13 (including 3 nuclear) whorls; nuclear whorls smooth and rounded; axial sculp ture on first 4 post-nuclear whorls of about 15 rounded riblets extending unconstricted from suture to suture; later axial sculpture terminating near the center of the whorl as slightly offset, rounded tubercles below w hich the whorls are somewhat spira _ lly excavated between the central tubercles and another opposing and similar set crowding the suture; spiral sculpture of 3 to 4 narrow impressed lines on earlier whorls, increasing in number on later whorls, all weakly overrunning the axials; suture di _ stinct, narrowly grooved and flexuous; base with two pairs of distinct impresse _ d spiral lines, the upper set being nearer together. Canal short; outer lip missing. Cotypes (Cat. No. 3521280 U.S.N. M.). These measure: the larger specimen (7 whorls),-alt. 12 mm., greatest diameter 3.6 mm.; smaller specimen, alt. 9 mm., greatest diameter 3 mm. 'Type locality: Well (depth 65-. 100 ft.) at Kissimmee, Osceola Co., Fla., Geo.C. Matson, collector, 1908. Geologic horizon : Probably Miocene. This species is related _to Terebra (Acus) concava (Say), but differs from the latter in having no distinct subsutural band, a spiral compres sion at the anterior of the whorl, a smaller initial nuclear whorl and fewer . revolving strire on the base. COLUMBELLA (ALIA) MATSON! N. SP. Plate I, Figures 3 and 4 . . . Shell small, solid, about six-whorled -(tip decollated) ; spire smooth, elevated, evenly conical; whorl s slightly convex, marked by three or four narrow, dim, brownish colored, spiral bands, slightly elevated on the an terior of the body whorl; suture somewhat appressed; shoulder of body whorl angled; base and pillar marked by thirteen wide, rounded, raised bands separated by narrow channels, .running parallel with and extending nearly to the angled shoulder; aperture moderately wide; 

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46 FLORIDA GEOLOGICAL SURVEY-15TH ANNUAL REPORT pillar slightly tvvisted ; outer lip, within, with seven denticulated ridges, the posterior one being the largest; inner lip with callus upon which an irregular ridge extends parallel with and close to the outer margin. Type (U. S. N. M. Cat. No. 352278). This measures: length 10.2 mm. ; greatest diameter 4.2 mm. Type locality: Well (depth 65-100 ft.) at Kissimmee, Osceola Co., Fla., G. Matson, collector, 1908. U. S. Geol. S .urv. Sta. No. 5016. Geologic horizon.: Probably Miocene. Discussion: This species is closely related to the northern Miocene form, Astyris com1nunis (Conrad) ; but in the former, the suture is only slightly appressed, the bands on the more numerous, extending farther up the basal slope . In addition, uA. in some specimens, shows distinct traces of narrow color-bands extending across the \vhorls in a direction nearly parallel with the axis of the shell and slightly flexuous." ('See Dall, \V agner Free In st. Sci., Vol. III, pt. 1, p. 138.) When the new species is con1pared with Astyris_ profund . Dall, the suture of the latter is found to be more appressed, the whorls more inflated, and the basal sculpture finer and more narrowly anteriorly confined. This ne\v species is named in honor of the collector, Mr. George C. Matson. CAECUM PUTNAMENSIS N. SP. Plate I, Figures 1 and Shell sn1all, thin, arched, and slightly tapering; surface aln1os t smooth but under magnification shows faint, irregular annulations and gro\vth lines; posterior end of tube very near the margin, slightly im-. . pressed, forn1ing a narrow, low, and inconspicuous ring; plug smooth, hemispherical and extending a little beyond the margin of the tube; mucro small, short, rounded and situated near the margin and a little to the right of the median plane of the slt ell; anterior end of tube swollen, forming a narrovv ring ne?r the n1argin ; anterior margin entire. 

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TERTIARY AND QUATERNARY PALEONTOLOGY, NORTHEASTERN FLORIDA 47 ' Cotypes (Cat. No. U. S. N. M. 352276, spec. A; 352277, spec. B). These measure: length,-specin1en A, ; specin1en B, 2.3 mm. ; diameter of aperture,-specirnen A, .6; speciJllen B, . 7 nun. ; diameter posterior encl,-specitnen A, .5; specimen B, .5 n1tn. Geologic horizon: Upper Pliocene or lower Pleistocene. Type locality: One-half mile above A. C. L . R. R. bridge over St. Johns River,. Putnam Co., Fla., five feet above high-water level and seven feet below surface. F. G. Clapp, collector, U. S. Geol. Surv., Sta. No. 6096. Discussion: This species some\vhat re s en1bles Caecu1n car_olinia-nun'l. Dall, but differs from the latter in having an anterior ring, a. more rounded plug, and lacking longitudinal sculptured strice. It is closely related to Caecu1J'IA chipolanu11"' Gardner (an unpubli s hed 1\IIs. ) species from the Chipola marl men1ber of the Alun1 Bluff forn1ation, b-ut the latter possesses an anterior and is a much heavier and more tapering s hell. CARDITA (CARDITAMERA) OSCEOLAENSIS N. SP. Plate I, Figures 11 and 12. . . Shell very thin, small, ovate; beaks not prominent, slightly twisted forward, situated at the anterior third of the valves; lunule long, moder ately impressed ; anterior side and middle of valves rounded; posterior side steeply sloping; posterior dorsal margin nearly straight, sloping at a low angle; anterior dorsal margin. sloping and slightly undulated; posterior n1argin nearly straight, truncating the end, making nearly right-angle with the dorsal margin and a rounded edge with the ventral ; anterior margin rounded; ventral margin arcuate. Shell sculpture4 radially by 20, _rather low, rounded ribs, nodulous about the beaks and roughened pistally by transverse ridges or imbricated growth lines. 'vVhole surface sculptured radially by fine, indistinct lines and transverse ly by rather fine imbricated growth structure. Inter-radial spaces about one and one-half as wide as ribs on the anterior and center of the dis _ k, but narrower at posterior angle where ribs widen out. Lateral teeth small ; anterior cardinal slender and prominent. Interior surface markedly fluted, reversing external sculpture and showing a pecten-like appear ance. 

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48 FLORIDA GEOLOGICAL SURVEY-15TH ANNUAL REPORT Type (Cat. No. 352275 U.S.N. M.); This measures: length of left valve 12.4 mm.; height 8.5 ' mm.; diameter (double) 6 mm. Geologic horizon: Probably . Miocene. Locality: Well at Kissimmee, O . sceo la Co., Fla. , (depth 65-100 ft.). G. C . Matson, collector, 1908 . Discussion: The thinne s s of the s hell a pproache s C . cath:aria Dall , but in the new species the posterior angled edge i s less drawn oqt, the dis k is more rounded and the shell more nearly equilateral. The shape of the shell resembles C. vauglwni Dall, but the latter is much he a vier and more robust in every way. I am unable to find a very close relative to the described species. Fig. 1. Fig. 2. Fig. 3. Fig. 4. Fig. 5. Fig. 6. F'ig. 7. Fig. 8. Fig. 9. Fig. 10. Fig. 11. Fig. 12 . Fig. 13. Fig. 14. EXPLANATION OF PLATE I putnamensis n. sp. Cotype, (x 10). U. S. N . M. Cat. No. 352277. Crecum putnamensis n. sp. Cotype; (x 10). U.S.N. M . Cat. No. 352276. Columbella (Alia) matsoni n. sp. Ventral view, Type (x 3). Columbella (Alia) matsoni n. sp. Dorsal view, Type (x 3). Nucleus restored. . Corbula inrequalis Say, var. A. Exterior of right valve (x 2). Station 5869, DeLan d, Fla. , (stratum No.3). U .S.N. M. Cat. No. 352286 . Corbula inrequalis Say, var. A. E x t erio r of l eft val ve of anot h e r speci men (x2). Station 5869, DeLand, Fla., (stratum No.3). U .S.N. M. Cat. No. 352286. Corbula inrequalis Say, var. B. Ext'erior of left valve (x 2). Station 5869, DeLand, Fla., (stratum No. 3). U . S . N. M. Cat . . No. 352287. Corbula inrequalis Say, var. B . Exterior of right valve {x 2) . S tation 5869, (stratum No. 3). U . S. N. M . Cat. No. 352287 . • Terebra (Acus) kissimmeensis n . sp. Larger cotype (x 3). Terebra (Acus) kissimmeensis n. sp. Smaller cotype (x 5). Card ita ( Carditamera) osceola en sis n. sp. E xterior of left valve. Type (x 3). Cardita ( Carditamera) osceolaensis n. sp. Interior of left valve. Type (x 3). Area transversa Say. Light form. E x t erior of left val ve (x t lh) . Sta tion 5869, DeLand, Fla., (stratum No.3). U . S. N . M. Cat. No . 352281. Area transversa s ay. Light form. Right valve of anot h e r specimen (x Station 5869, DeLand, Fla. , (stratum No.3). U . . S. N. M. Cat. No. 352281. . . 

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TERTIARY AND QUATERNA RY PALEONTOLOGY, NORTHEASTERN FLORIDA 49 N til <q 1 2 3 4 7 (:) 5 Q) ' / e} g . 6 10 12 11 13 14 PLATE I 

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50 FLORIDA GEOLOGICAL SURVEY-15TH ANNUAL REPORT • ' Plate II. 1 & 2. Mulinia contracta (Conrad). Left valve (x 1 0). Stati on 5869, DeLand, F l a., (stratum No.3). U. S. N. M . Cat. No. 352283. Figs. 3 & 4. Mulinia sp. near M. caloosaensis Dall. Left valve (x Station 4865,% mile south of Nashua, Fla. U.S.N. M. Cat. No . 352284. Figs. 5 & 6. Mulinia latera lis Say. Heavy form. Left valve (x tlh). Station 5634, DeLand, Fla., (stratum No.1). U.S. N . M. Cat. No. 352285 . Figs. 7 & 8. Mulinia lateral is Say. Long form. Left val ve ( x l"lh). Station 5869, DeLand,. Fla., (stratum No. 3). U. S. N. M. Cat. No. 352282. 

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TERTIARY AND QUATERNARY P ALEONTOLOGY, NORTHEASTERN FLORIDA ) I PLA'I'E II 

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I I 

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A PRELIMINARY REPORT ON CLAYS OF FLORIDA 53 A PRELIMINARY REPORT ON THE CLAYS OF FLORIDA (ExcLUSIVE oF EARTH) BY OLIN G. BELL 

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54 FLORIDA GEOLOGICAL SURVEY-15TH ANNUAL REPORT ,. LETTER OF TRANSMITTAL MR. HERMAN GuNTER, State Geologist, Tallahassee, Florida. Sir :-I herewith transmit my manuscript and illustrations of A Preliminary Report on the Clays of Florida . The field and laboratory work ha v e been done and the report prepared in accordance with our agree ment of February 6, 1922. me to express n1y appreciation of the interest you have taken . in this work during its various stages and the assistance you have given in its prosecution. • Very respectfully, OLIN G. BELL. Cornell University, Ithaca, New York, November 12, 1923. 

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A PRELIMINARY REPORT ON CLAYS OF FLORIDA CONTENTS INTRODUCTION ................................................. .... .... Scope of Report ............................... . . . . .............. . Field Work ...................................................... . Previous Work on Florida C lays ...... .... ........... .............. . Acknowledgments ...... : ............................... ........... . CHAPTER 1: General Geology of Clays ......................................... . Definition ................... ............. .... ................ . Origin ................... ..................... ............... . Geologic Types of Deposits ................................... . Residual Clays ............. '. ........ ..................... . Sedimentary Clays ........... ............................. . Marine Clays ........................................ . Flood-Plain Clays . . : ...... . . . . . . . . ........ . . ......... . Lacustrine Clays ..................................... . Glacial Clays ........................................ . Aeolian Clays .................. ....................... . CHAPTER 2: Classification of Clays .................................... ...... .. . R . ' I 'fi . 1es s c ass1 cat1on ...... .......... ........................... . Grout and Soper's classification ..........................•.•••••• Parmelee's classification ...................................... . . CHAPTER 3: Mineralogy and Chemical Properties of Clays . . ... , ................. . Minerals in Unburned Clays .... .......... ....... ............ . Kaolin . ite ................................................. . Quartz Feldspar ...................... ........................... . Mica .................................. .................. . ................. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . • Ltmontte ........................... ...... . . . . ........... . Hematite ........................ ......................... . M t't . agne 1 e ............................................. . ... . Siderite ................................... ............... . Py .ri te ......................... .......................... . Calcite ................................................... . Gypsum ......................................... ......... . Rutile .................................. : ...... ........... . II meni te .................................................. . Glauconite ................................................ . Chlorite .................................................. . Dolomite ................................................. . Hornblende .............................................. . Garnet ....................................... ............ . V . . • t vtantte ................................................. . and Psilomelane .............................. . . . Minerals in Burned C lays :............. ............... ; ....... . Chemical Analysis of Clays ................................... . Chemical Effect of Various Constituents in Clays ................ . Silica ... ........... .... ................. . .......... ...... . AI umina .......................... ....................... . Iron oxide . ................................ ............. . Lime ..................... . . . . . Magnesia ................................................ . Alkalies .......... ..... . ...... ........................ . ... 55 PAGE 61-63 61-62 62-63 63 63 64-68 64 65-66 66-68 66-67 67-68 68 68 68 68 68 69-71 69-70 70 70-71 71-88 7177 71-72 72 73 73 '}3 74 74 74 74 74-75 75 75-.76 76 76 76 76 77 77 77 77 77 78 79-81 81-:-88 81 81 81-82 82-83 84 84 

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56 FLORIDA GEOLOGICAL SURVEY-.I5TH ANNUAL REPORT CONTENTS-CONTINUED PAGE Chemical Effect of Various Constitu en ts in C lays (Continued). T . . . I tan tum ......... : ................ ....................... . Water .............. . .............................. . ..... . Organ.ic Matter .......................................... . 84 8 4 85 Sulphur .......................... . . . .......... . ............ . 85-86 86-88 Soluble S.alts ............................... . . ........... . . CHAPTER 4: Physical Properties of Clays . ..... . ............ ................. ... . 89-99 89-90 90 91 91 Plasticity .............. .' ....... . . . . ... : ...................... . Color ............. : ........................................... . Texture .................... .................................. . Slaking ..................... .... ............... ........ . ..... . Shrinkage ................ . ............................. . . .... . 91-93 93-97 97-99 Fusibili ty .......... . . .......... .............................. . Porosity .................................................. . ... . Transverse ........................................ ... . 99 99 Bonding Strength ............................................. . CHAPTER 5: Tests Made Upon C lays ............. . .... . . ....... ..... ... . ...... . 100-103 CHAPTER 6: Kinds of ays and Their Uses ................ . . . . I .... ...... .... . Kinds of Clays ............................................... . Kaolin ................................ ................. . Ball-Clay .. ..... .................. ...... .......... ........ . • Fire-Clay ............................................... . Stoneware Clay ...................................... . . . . . Terra Cotta Clays ...................................... . • Sewer Pipe C lays ............ ................ ............ . • Brick C lays ................... .............. ........ . ... . Slip C lays ..................... . .......... ............. . . . Miscellaneous ....... .................. .................. . Uses of Clay ........ ...... ........... ....................... . CHAPTER 7: 1 04-106 1 04-106 10 4 104 10 4 104 104-105 105 105 106 106 106 Geologyof the Clays of F'Iorida ....... ............................. 107-119 Stratigraphy ................ .... ......... .......... , ........ .... . Table of Geologic in Florida ...................... : ..... . Eocene ........ ...... . ....................................... . 0 ligocene . .................................................. . Miocene ........ ; .............................. . . ....... . ... . Pliocene .................................................... . Pleistocene .................................................. . . Geologic Age, Occurrence and Distribution of the Clays ............. . Conditions of Sedimentation and Sources of Material ............... . CHAPTER 8: 107 107 107-108 108 108-109 109 109 109-117 117-119 Distribution and Description of Deposits by Counties. . . . . . . . . . . . . . . . 120-215 Alachua County .............................................. 1 22-124 Baker County ......... . . . ......... _...... . . . . . . . . . . . . . . . . . . . . . . 1 2 4-125 Bay County . ................ ............... . . . . . . . . . . . . . . . . . . 125 Bradford County .............. .-. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 25 Brevard County . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 125 Broward County ................ ...... . ......... .. . . . . . . . . . . . 125 Calhoun County ...................................... ........ 125-1 28 Charlotte County ................. ...... . . . . . . . . . . . . . . . . . . . . . 1 28 Ci trus County . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 128 Clay C9unty . .................. ........ ...... ................ 128-133 Collier County. (see Lee). Columbia County .. ..... .............................. . ... .. Dade County ................................................. . DeSoto County . ...................... ........................ . 133-134 134 134-135 

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A PRELIMINARY REPORT ON CLAYS OF' FLORIDA CONTENTS-CoNTINUED Deposi ts b y Counties (Continued). Dixie County .......................... ..... ................. . Duval County ................. .............................. . Escambia Cou nty ........................... ................. . Flagler Co unty ............................... ........ ....... . Franklin County ........................................... . Gadsden County ...... ....................................... . County ....................................... ... .... . Hamilton County ....... ..................................... . Hardee County .............. ... ............. ........ ...... . . . Hendry County (see Lee). 57 PAGE 135 135-138 138-157 157-158 . 158 1 5816 4 1 64 164-165 16 5166 Hernando County . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 166 -170 Highlands County ...................................... . . . . . . 170 Hil1sborough County . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 7017 2 Holmes County . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 172 Jackson Cpunty . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 2173 J efferson County .. ........................... : ............... 173-174 Lafayette County . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 4 Lake County .... : . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 174-1 76 Lee County .......... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 6 Leon County .................................................. 177-18() Levy County ... : . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 180-181 Liberty County ...................... .......................... 181-183 Madison County . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 183 Manatee County ........................................ : .... . 183-185 Marion County .. ! • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • 185-186 Monroe County . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 186 Nassau County ..................... . ........... .............. 186-189 Okaloosa County .. .................. .......... . . . . . . . . . . . . . . . 189 Okeechobee County . . . . . • . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 189 Orange County ............................................... 189-191 Osceola County .............. ............. ..................... 191-192 Palm Beach County . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 192 Pasco County ........ .... . ................. : ................. 19 2 -194 Pinellas County . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 194 Polk County ................................................. 194-197 Putnam County ........................ ........................ 197-19 9 St. Johns County •........................ ................... .". 200-201 St. Luci e County . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 201 Santa Rosa County .......................... ................. 201-205 s arasota County .......................................... ... : 206 Seminole CountY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 206 Sumter County ............................................... 206-207 Suwannee County ............. : . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 207 Taylor County . ................ .............................. 207 -208 Union CoUnty . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 208 Volusia County ................... ........................... 298 211 Wakulla County . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 211 Walton County .................. ........•................... 211-213 Washington County ......................... ..... ............ 214-215 

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58 FLORIDA GEOLOGICAL SURVEY-I5'l'H ANNUAL REP OR T CONTENTSCoNTINUtD PAGE CH APTER 9: Sedimentary Kaolin ........... . ............ .. ... ................ . 216-241 Terminology .... .......................... . .... ... ............ 216-217 Distribution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 217-219 D . . t' 219 escrtp t on .... . ...................... . .......... ........... . Ge.ol?gic Age ... . . : . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 2 1 0 rtgtn . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 1226 History and Development . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 226 Propertie s ..... ....... ......................... .............. 226-232 Mineralogy .... : . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 232 Uses .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2322 3 3 Methods of Mining . . ........... .............................. 233-234 D istribution by Counties ..................... ................. 234-241 Alachua County . . .......... ....... . ....... ............... 234 235 Citrus, Clay and DeSo to Counties. . . . . . . . . . . . . . . . . . . . . . . . . . 23 5 Hernand9 County . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 235 Highlands County . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 235 Lake County ......... . : . ........................... .. .. .. 2 35-238 Levy County ................... ....... : . . . . . . . . . . . . . . . . . . . 238 Marion County . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 238 Pasco County . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 240 Pol k County ........................ . . .... • . . . . . . . . . . . . . . . . 240 Putnam County . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 240 Suwannee County . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 241 Walton County . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 241 CHAPTER 10: DeveJopment and Possibilities of the C l a y Industry i n Florida ........ 242-250 Early History . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 242 Recent History ......... : . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 242-243 Present Statu s ............................................... . 243-245 Present Tendencies ................ ............... ............ 245-249 General Development and Expansion in F lorida . . .... ....... 245-246 Sources of Structural Materials ........................ .. .. 246-247 Substitutes for Clay Products .............................. 2 47-248 Attitude of Some Contractors and Builders toward F lorida Products .................... . ............. I • • • • • • • • • • 248 Adaptibility of Florida Products .............. . ............ 248-249 Reasons for Failure of Many F lorida Ventures. . . . . . . . . . . . . . 249 Possibilities and Reserves .......... ............. . ............. 249 250 CHAPTER 11: Methods of Prospecting for C lays .................................. 251-253 APPENDIX A. Statistics of Production of Brick. . . . . . . . . . . . . . . . . . . . . . . . . . . 254 APPENDIX B. Fusi on Points of Seger Cones. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 5-257 APPENDIX C. Directory of F lorida Clay Workers .......... ......... . . . .'. 258 APPENDIX D . Bibliograph y of F lorida C lays . ......... ................... 259-260 INDEX . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 1 

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A PRELIMINARY REPOR't ON CLAYS OF FLORIDA 59 LIST OF ILLUSTRATIONS FIGURE . PAGE 1. Chart showing range of firing temperatures for clay products.......... . 98 2 . Map showipg location of clay-working . . . . . . . . . . . . . . . . . . . . . . . . . 120 3. General View, Campville Brick Co., Campville, Alachua County........ 121 4. Clay pit. Guilford Bros. Brick Co., Blountstown, Calhoun County. . . . . . 126 5. Method of stacking a kiln for burning. Guilford Bros. Brick Co. . . . . . . . 126 6. Un. Ioadirig a kiln. Guilford Bros. Brick Co........................... 127 7. Black Creek Barge Landing, near Middleburg, Clay County. Formerly used for shipping brick . : . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 129 8. Clay pit. Gamble and Stockton Brick and Tile Co., South J acksonviiie, Duval County .......................................... . . . . . . . . . 136 9. Circular down-draft kiln. Gamble and Stockton Brick and Tile Co..... 136 10. Bluff on west bank of Escambia River at Dexland, opposite Gonzales. Interbedded clays ( Citroneiie Formation?) in lower half; Pleistocene sands in upper half . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 139 11. View of a pit face showing cross-bedded clays (probably Pleistocene), Dolores Brick Co., Molino, Escambia County .............. . . . . . . . . 141 12. General view of clay pit (Citronelle Formation?), Barrineau Bros. Brick Co., Quintette, Escambia County .......... :. :. . . . . . . . . . . . . . . . . . . . . 141 13. Layer of limon. ite overlaying cross-bedded sand. The sand is underlain by clay. Barrineau Bros. Brick Co., Quintette; Escambia County... . 1 42 14. Pink pottery clay ( Citroneile Formation?) exposed in bluff at Gu 11 Point near Pensacola, Escambia County ............................ .... 144 15. Unconformity between two clay beds exposed in a pit five miles north of Pensacola, Escambia County....... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 144 16. Mining clay with steam shovel, Dolores Brick Co., Molino, Escambia County . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 147 17. Dump car for conveying clay from pit to press. Dolores Brick Co., Molino, Escambia Count)' ................ :. . . . . . . . . . . . . . . . . . . . . . . 147 18. View of drying shed method of stacking brick for drying. Dolores Brick Co. , Molino, Escambia County...................... . 148 19 . Plant and drying . sheds, Dolores Brick C<?., Molino, Escambia County.... 150 20. Drying tunnels, Macmillah Brick Co., Molino, Escambia County........... 150 21. A battery of circular down-draft kilns. Dolores Brick Co., Molino, _ Escambia County . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 150 22. General view of Barrineau Bros. Brick Plant, Quintette, Escambia County 152 23. General View, Ocklocknee Brick Co., Lawrence, Gadsden County... . . . . 163 24 . Setting a kiln. Morris and Blumer Brick Co., Brooksville, Hernando County . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 167 25. Clay pit, Keystone Brick Co., Whitney, Lake County................... 175 26. View showing kiln sealed ready for firing. Keystone Brick Co., Whitney, Lake County . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 5 27. Clay exposed on Apalachicola. River at Estiffanulga Bluff, Liberty County 181 28. "Old Brick Yard Landing," on St. Marys River, Nassau County......... . 187 29. Loading cars, Callahan Brick and Tile Co., Callahan, Nassau County... 187 30. Orlando Pottery, Orlando, Orange County. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 190 31. A potter at work, Orlando Pottery . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 190 32. Portable press in operation. Allentown Consolidated School, near Milton, Santa Rosa CoUnty . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 202 33. Partially built scove kiln in rear ground with freshly molded brick stacked out in open air to dry in foreground. Allentown Consolidated School, Santa Rosa County .............................................. -. 204 34. Firing a scove kiln. Allentown Consolidated School . . . . . . . . . . . . . . . . . . 204 35. Brick machine, Hall Brick Co., Chipley, Washington County... . . . . . . . . . 215 36. Drying . shed, Hall Brick Co. , Chipley....... .. .. . . .. . .. .. . .. . .. . . .. . .. 215 37. General View of Edgar Plastic Kaolin Company's Plant, Edgar, Putnam County . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 218 Removing overburqen. Edgar Plastic Kaolin Co., Putnam County... . . . 219 

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60 FLORIDA GEOLOGICAL SURVEY-I 5TH ANNUAL REPORT LIS'T OF ILLUSTRATIONS-CoNTINUED FIGURE PAGE 39. Dipper on dredge boat dropping crude clay into bin from w hich it is pumped up to washing plant. Edgar Plastic Kaolin. Co. . . . . . . . . . . . . 220 40. Trough leading to settling vat. Edgar P l astic Kaolin Co.............. 220 41. Filter presses, Edgar Plastic Kaolin Co . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 223 42. Plant of Florida China Clay Co., near Okahumpka, Lake County . . . . . . . . 225 43. Removal of overburden by h ydraulicking. Florida China Clay Co., Okahumpka, Lake County . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 225 44. View' of dredge boat used in mining sedimentary kaolin, Florida China Clay . Co., near Okahumpka, Lake County . . . . . . . . . . . . . . . . . . . . . . . . . . 2?.7 45. Near view of dipper on dredge boat. Refuse S'\_nd in background. Flor-ida China Clay Co ......... ............................... : . . . . . . 227 46. Entrance to sand traps, Florida China Clay Co . . . . . . . . . . . . . . . . . . . . . . . . . 228 47. Settling troughs, Florida China Clay Co. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 228 48. Settling vat, Florida China C lay Co......................... . ........ 231 49. Settling vat partially filled, Florida China Clay Co..... .. ... .......... . 231 50. Empty settling vat, Florida China Clay Co . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 232 51. Sluice for returning water from filter presses to clay pit. Florida China Clay Co. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 233 52. Motor used in loading cars. Florida China Clay Co ... . . . . . . . . . . . . . . . . 237 53. Loading cars. Florida China Clay Co. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 237 54. Dredge boat (in background), sluice w ays and sand traps (foreground). Lake Cou . nty Clay Co., Okahumpka, Lake County... . . . . . . . . . . . . . . . . 239 55. General view of drying sheds, warehouses and loading docks. Lake County Clay Co. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 239 -.. 

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A PRELIMINARY REPORT ON CLAYS OF FLORIDA 61 INTRODUCTION. SCOPE OF THIS REPORT In this investigation no attempt has been made to cover completely the clay deposits of the entire State of Florida. It is intended to be only a preliminary report which will make available at an early date data con Gerning the clays within reach of transportation. It will, moreover, furnish a basis or foundatron upon which further and more extensive work on the clay _ resources of the State can be based as it becomes ex pedient do so. This report ; therefore , considers only the clay deposits known at the time the field work was carried on and situated not more than two miles from water or rail transportation. Unless a clay deposit is . of very exceptional quality, it is not prob able that it will be d _ eveloped within the next few years if more than a mile or so from a railway. No definite distance from transportation, however, can be placed as a limit for workable deposits. The quality of the clay, availability and cost of fuel, labor, . cost of mining or manu facturing, cost of equipment, proxitnity to n1arket, prevailing market price, distributing facilities and numerous other local factors whether or not a clay deposit be profitably worked. Depo sits of clay not within an distance from transportation are potential sources of supply and can be considered only as reserves. As general development proceeds in the State these deposits will become useful. Clay deposits underlying a great thickne ss of overburden are like wise not considered in this report. -Here agait1 the c 0 nditions mentioned above apply. The greater the overburden w hich must be removed the greater the cost of production. Clays which are_ now at too great a . depth to be profitably worked may become workab le at so me future time . In most" cases the thickne ss and extent of a clay . deposit were not given any further consideration than to determine whether or not suf ficient clay was available to supply a n average demand for a rea sonab le period of time. In many deposits enough clay . was seen to be at hand to supply an average brick plant for more than thirty years . A depend able estimate is that 750,000 bricks can be made from an acre foot, ( 43, 560 cubic feet,) of .clay. A of 12,000,000 annual capacity wou ld utilize 15 acre-feet of clay per yea r. The thickne ss and extent of a clay deposit and the cost of acquiring the property are factors, therefore, 

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62 FLORIDA GEOLOGICAL SURVEY-15TH ANNUAL REPORT which should b e given thorough consideration by a prospective manu facturer . The ain1 of this report is to guide the manufacturer to deposits worthy of his notice and to furni s h owners of such clay deposits knowledge of their occurrence, properties , and usefulnes s and it is hoped that this work will be of son1e assi s tance in furthering the developn1ent of the clay industries of Florida. The general geology, clas s ification, n1ineralogy, chemical and phy properties, and u ses of clays are briefly discus s ed in this report. 1\I.Iuch has already been published on these topics and the di s cussion which follows i s b y no n1 eans exhaustive. It. sun1n1arizes the more important facts that have been brought out by previous investigators. This is done to answer -numerous inquiries continuously b'eing received by the Survey regarding the con11non properties of clays, jand also to enable those people who have neither time nor facilities to consult the other publications to have the benefit of this knowledge which may fasilitate their use of the data bearing on the Florida clays. Adequate footnote references are made to other writers so that readers may consult the principal papers previously published dealing with clays. A discussion of the n1ethods of of cla y products, descriptions of "the individual brick plants and nun1erous other sections have omitted in order to conserve space . Nun1erous photographs, hovvever, have been u se d to show the t y pes of machinery employed, types of kilns in operation, tnethods of clay n1ining , and general plan and arrangements of plants. Fuller's earth, a clay with s pecial properties but little or no ity, has been discussed at length in previous reports of the Survey, particularly the and Sixth Annual Reports, and the time and .funds available did not pern1it a . further treatment of it in I the present paper. FIELD WORK The field work was carried on cluripg the season of 1922. At this time all acces s ible clay depo s its of which the State Geological Survey had any knowledge were vis . itecl. Inquiries made in each during the progress of the work brought many additional deposits to notice. In case the deposit was exatninecl as thoroughly as tin1e pern1itted and if the clay seemed promising at all a representative sample vvas 

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A PRELIMINARY REPORT ON CLAYS OF FLORIDA 63 taken for laboratory tests. The tests were made by the writer at Corneli University, Ithaca, New York. In a few cases satnples of clay from de-. . . not known at the time of the field work were later sent to the testing laboratory. PREVIOUS ON FLOR1DA . CLAYS Much work . has previously been done on the clays of. Florida, par ticularly on the sedin1entary kaolins of Putnan1 . and . Lake counties and on the fuller's earth of Gadsden and Manatee counties. Most of this tnaterial has been published by the United r States Geological Survey, but some . has appeared in the . Annual Reports of the State Geologist of . .. Florida and some scientific journals. The dealing with nhe clays of the State has been freely used. Credit for such information has been given in the footnote references in each case. ACKNOWLEDGMENTS The writer desires to express his deep appreciation of the and patient help accorded him by nun1erous individuals during the progress of this work. Dr. H. Ries kindly granted the of the clay testing laboratory at Cornell University, and has given the author many helpful suggestions, M_r. Herman Gunter, State Geologist, rendered much assistance in planning a .nd carrying out the field work. Mr. T. C. Adams, a graduate at Cornell University, kindly permitted the use of a chart which appears as Fig. 1. A v .e.ry great number of people in the various localities rendered invaluable aid, many gave liberally of theit: time, in guiding and directing the party to the more important clay deposits. An1ong these may be mentioned 1 Mr. J. E. 'Worthington of Lake Wales, Mayor F. D. Cosner and Mr. <C. B. Taylor of Dade City, Mr. W. A Fulton of Brooksville, Dr. T. S. Ken nedy of Williston, Mr. W. B. Powell . of Tavares, Secretary of the Lake County Chamber of Commerce, Mayor C. A. Vaughn and Mr. Allen Strait of Umatilla, Mr. C. H. Tedder, Secretary of the Chatnber of Com tn erce, Live Oak, Mr. I-I. D. Mendenhall, Consulting Engineer, of Lake land, and numerous The brick and pottery m anufacturers and superintendents of clay mining plants were uniformly courteous and generous in their assistance while the party was visiting their plants. 

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64: FLOR IDA SURVEY-I 5 ' l'll ANNUAL REPORT GENERAL GEOLOGY OF CLAYS D EFINITION The gen era l u sage of the tenn clay i s a very broad one and include s a large varie t y of s ubst ance s . This lib era l u sage of the t e rm has devel oped as a r es ult of clay being one of the mo s t abundant natural prod u cts. It i s f ound in so n1e forn1 in practically every locality and is used for a great variety of purposes . No one definiti on of clay , therefore, can sati sfacto ril y fulfill all r equ iretn ents. This i s partly due to the fact ' that the present kn o \vledge of cia) s i s far frotn complete, but more especially due t o the fact that clays vary greatly in their properties and u s e s . Not\\ o days are e_'{actly alike. In any sense of the term cla y i s a s ubstance occurring in nature which i s pla stic \ v h e n \vet, capable of b eing molded, preserves its shape upon b e in g d ried, and changes to a hard rock-like s ubstance on being fired. Ries1 define s clay "as ;.tn earthy material occurring in nature \ vhose pron 1inent pr.operty is pla s ticit y when wet." Merrill2 cla y " a s a \ v hole , a s heterogeneous aggregates of h y drous alutninous silicates, free s ilica, and ever-varying quantities of free iron oxides and calcium n1agnesium carbonates, all in finely comminuted condition. Orton3 says : "Strictl y s peaking, h o v v ever, the term applies to a single mineral , viz., s ilicate of alumina or kaolinite." Wheeler4 says: "The scientific definition of the term clay i s a n1ore or l ess pure variety of the nrineral kaolinite, the hydrous s ilicate of alumina." He a lso gives the following a s the popular definition of a clay: "Clay is an earthy tnaterial that becomes plastic when wet." Thus it is se e n that the principal definition s take t wo form s, viz., those based upon the property of pla sticity and tho se bas ed upon the mineral Both of thes e correct in that all clays are IRies, H., C l a ys, Their Occurrence, Properties ancJ Uses, p. 1, 1908. 2Merrill, G . P., The Non-Metallic Minerals, p. 221, 1910 . 30rton, E., The Clays of Ohio, Their Origin, Composition and Varieties. Ohio Geol. Survey,-VII, Part I, p . 46, 18 . 93. 4Wheeler, H. A., Clay Deposits, Mo. Geol. Survey, XI, p. 17, 1896. 

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A PRELIMINARY REPORT ON CLAYS OF FLORIDA 65 plastic to a greater or less degree and probably all contain some forro of hydrous altunintun silicate, in widely varying quantities.* . ORIGIN A clay is in all cases a secondary product resulting from the decorr. position and disintegration of pre-existing If the clay remain _ in the space formerly by the paren t it is said to be residual. If, however, the clay is transported, either by wind or water, and then deposited it is tern1ed a transported or sedimentary clay. The breaking dovJn of one rock and the resultant formation of clay is one of the processes of rock \veathering. This includes bo t h chemical action (decomposition) and action (disintegration) which are often carried on at the same time and are very closely related. Weathering takes place chiefly through such atn1osp heric agencies as rain, frost, \vind, changes in temperature, through organic agencies as plants and animals, and through the action of atmospheric gases. rocks are the primary sources of all other rocks and are then the original sources of all cla ys . Limestone or shale residual clays are only indirectly derived from igneous rocks and have previously gone through one or more processes of weathering and sedime ntation. Rocks containing feldspar may into cla y. In f ac t , it \Vas formerly that c;tll clay resulted from the weathering of feldspathic rocks. Ries1 has pointed out that "there are some rock species, how ever, that contain no feldspar (such as s erpentine), and others \vith very little (as some gabbros), which, on weathering, produce some of the most plastic clays kno,:vn." In the proce s s of weathering the more in soluble portions, such as sotne of the aluminum silicates, accumu late and the more soluble constituent s , a s lime, magnesia , p otash, soda, and sometimes silica, are carried a\vay. During the \veathering process the clay which con sis t s of very fine particles may be left intimat ely mixed \vith larger particles of sand and other material. If this mixture is carried away by the ac tion of running \Vater a s eparation of theclay from the coarser material may result. Such • a separation . has often been the cau s e of the formation of large bodies *So il investigators have still other definitions for day based on fineness of grain rather than plasti city or chemical compo sition, one being all soil parti cl e s less than :005 mm_. in diameter, and another that part the soil which will remain s uspended m an 8-mch colu m n of water for 2+ h ou rs. Shghtly coarser and non-plastic material is distinguished as silt. ( See Hilgard, So ils, pp. 57-62, 83-85, 19 0 6. ) H. G. 

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66 FLOR . IDA SURVEY-15TH ANNUAL REPORT of clay free from sand. In other . cases velocity and current conditions may be such as to transport and deposit some sand with the clay result ing in the formation of a sandy clay. After a clay deposit ha s been f_ormed it may be modified in various ways. Fo. r example, the !JlOre sol uble eletnents may be leached from i t and carried away by circulating waters. Other mineral matter may, under certain conditions, be carried in and deposited by the same process. GEOLOGIC TYPES OF DEPOSITS There are in general two important types of clay deposits: One is termed re sidua l because it is the residue re sulting from the weathering or decomposition of a _ rock in place . . other i s termed sedimentary or transported as the material has been transported from a fanner posi tion and deposited as sediment by the action of wat e r or wind . It i s not alwa ys possible to distinguish these two types in the hand specimen. In Florida it is also sometimes difficult to apply the fundan1ental distinc tions in the field as sufficient evidence is often inaccess-ible. A residual clay is found where the decay of the parent rock has gone on without interruption for a lon g period of time and where the resulting products have not been carried away by erosion. Such deposits usu ally take the form of a clay mantle or which is co-extensive with the parent rock. Their thickness is often very .irregular depending upon the d epth to which weathering has proceeded and the amount of erosion which has followed. Residual clays may re sult from a variety of sedimentary, igneous or metamorphic rocks . The most important residual clays are derived from the decompo s ition of rock ? high in feldspathic constituents. Such clays, if high grade, usually must be purified by washing in order to remove undesirable ingredients as quartz, mica, etc. They a r e frequently highly colored by iron compounds and these are not completely re movable. Deposits of residual clay are u s uall y characterized by a gradual passage from pure clay at or near the surface to the unaffected parent rock below. In thi s pa ssage from the surface downward first a zone of fully formed clay is encountered which gradually passes into a zone of badl y decayed angular rock fragments, then into a zone of only partially altered fragments and finally into the fresh unaltered parent rock. There is no sharp line of demarcation or contact between the zones above n1en-

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A PRELIMINARY REPORT ON CLAYS OF FLORIDA 67 tioned.1 This, however, i s not ca s e in cla y s residual fron1 lin 1 e s tone. In limestone residual clays, on the other hand, there is . a sudden change fron1 clay to the limestone paret:J.t rock below. Mo s t surfa-ce water, particularly rainwater, carries dissolved . in it some carbon dioxide gas, ( C02) resulting in the formation of an acid, (carbonic acid, H2COs), which attacks the calciutn carbonate of the limestone forming a com pound, (calciutn b i carbonate, Ca(HC03)2), which .is soluble in water. This process in Florida and els ewhere is greatly augmented by the addi tion of organic acids furnished by plants and decaying vegetable mate rial. Thus litn.estone is decompo s ed and the s oluble portion carried away in solution. Most litnestones, however, have varying amoul!ts of im purities, as clay substance, which is not affected by the weak acids and is insoluble in water. It therefore ren1ains as residual clay when the limestone is . dissorved. Thus when the decomposition of the limestone has occurred to any depth there is a sharp contact between the clay and the underlying limestone because this change is not due to a gradual breaking down of the minerals in the rocks, as in the case of the feld spathic rocks; Sedimentary clays are those which have been transported by the action of water or wind from their point of origin and deposited else where in the form of stratified . beds. Thus clay particles are swept from the land surface in the proce s s of er<?sion apd carried to lakes, estuaries, or the sea, etc., where they to the bottom of the quiet water as sediments. Such deposits may have no genetic relationship with the beds below or above. Deposits of sedimentary clay are sometimes of great thickness, but are n1ore frequently rC:lther thin. They may be of great purity or they may be accon1panied by much impure material as n1ineral fragments (sand, mica flakes , etc.) or vegetable matter. Thes e clays may have a great lateral extent or the y may be confined within a small area. They ar:e at times interbedded with other sediments a . nd may even be crossbedded. S01ne depo s its exhibit marked ities of thickne s s, becoming thicker in one place and thinning , out in lFor a complete discussion of the processes involved in the formation of residual clay see any of the following: Buckman, H. 0., The Chemical and Physical Processes Involved in the Formation of Residual Clay, Trans. Am. Ceramic. Soc., Vol. 13, p. 336, 1911. Merrill, G. P., Rocks, Rock Weathering and Soils, p . 289, 1913. Ries, H., Clays, Their Occurrence, Properties and Uses, p. 7, 1908 . 

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68 -FLORIDA GEOLOGICAL SURVEY-15TH ANNUAL another. Likewise distinct changes in the character of the clay may occur from place to place in the same bed. There are several forn1s of .sedin1entary clay deposits based upon the conditions of sedimentation. The follo wing with the exception of the last two, glacial and aeolian cla ys, are all found in Florida. Marine Clays-Fresh water in rivers, etc., tnay contain . n1uch clay substance, consisting of the very fine s t and lighte s t particles , whi c h it carries in This acts as a solution of clay in water. When this fresh water becomes n1ixed w ith sea water the cla y flocculate s and is de posited on the s ea floor, or, as is frequently the case, in estuaries or lagoons along the coast . . Extensive clay deposit s are thus found. Flood-Plain Clays-Strean1s carrying clay material in suspension or rolling it along on the stream floor often deposit n1uch of it in the adjacent lowlands during periods of flood . Sub s equent overflow s de posit additional layer s . Extensive flood-plain deposits are often formed in this manner along_ larger streatns and in their deltas. Flood-plain clays are extremely variable in their nature and are often calcareous or sandy. Lacustrine ClaJISClay n1aterial carried by streams into lakes or ponds gradually settles to the bottom of the quiet water to form a de posit of clay on the lake floor. Such clay s n1ay be of great purity or they tnay be mixed with a grea_ t an1ount of,sand or other Glacial Cla.ys-These are son1etin1es tenned till or bowlder clay. These are which are of heterogeneous character and usually imJ?ure, formed by the grinding of rocks or rock fragtnents by glacial action and deposited b y the ice as it n1e:te:l or by the resulting water in the redeposition of the Deposit s of this type are only found in glaciated regions. None exist in Florida. Aeolian of clay forn1ed by the e!.C ion of the wind are termed aeolian clays. In arid. regions clay in the of dust is blown about and sometimes accumulates in beds. Son1e loess clays are believed to have been . deposited in this manner. No such clay s are known in Florida. 

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A PRELIMINARY REPORT ON CLAYS OF FLORIDA 69 CI-IAPTER II CLASSIFICATION OF CLAYS Clays ma:y be clas s ified in a variety of ways, according to their origin, mode of occurrence, prop erti es, or u s e s . No . clas s ification y e t proposed , however, has s ati sfac torily treated such a diver sity of factors. A classification ba s ed upon t he origin would l : e of sp ecial int e re s t to the geologist, while a ceramist wo uld te tnor e keenl y interested in o n e baseq upon their physical prope rtie s . A cla ss ification ba sed upon the u s e s of cla ys is the least satisfact o r y of any clue to the fact that there is a ve r y great range in the kind of clay p se d for any one purpose, and that one clay may be u se d for s e ve ral different purpose s. In the pa s t three decades no le ss than nine1 separate cla ss ifica tion s have appeared in the literature dealing w ith cla ys . none of . . these are satis f ac tory in every respect, three of then1 d eserve careful consideration. Ri es's2 classification is based primaril y on the geo l ogica l occurrence and seco nd a ril y on the firing q t talitie s of clays . It follows: A. Residual clays. (By decomposition of rocks m situ.) I. Kaolins or china clay s . White-burning. (a) Veins, derived from pegmatite. (b) Blankets, deposits, derived from e x tensive areas of tgneous or metamorphic rocks. (c) Pockets in limestones, as indianaite. II. Red-burning residuals, derived from different kinds of rock. B. Colluvial clays, representing deposits form e d b y wash from the foregoing and of either refractory or non-refractory character. lOrton, E., Clays of Ohio, Ohio Geol. Survey, VII, p. 52, 1893. Wheeler, H. A., Clay Deposits, Missouri Geol. Survey , XI, p. 25, 1896. Ladd, G . E . , Preliminary Report on the Clays of Georgia, Georgia Geol. Survey, BulL 6A, p . 12, 1898. . Buckley, E. R., The Clays and Clay Industries of Wisconsin, "Wis. Geol. Survey Bull. 7, Part I, p. 14, 1901. Orton, E., Jr., Quoted by Beyer, S . W., and I. A., Techno logy of Clays, Iowa Geol. Survey, Vol. XIV, p. 40, 1903 . . Grimsley, G. P., Clays, Limestones, and Cements , West Va. Geol. Survey, Vol. III, p. 70, 1905. . Ries, H., Clays, Their Occurrence, Properties and Uses, p. 27, 1908. Grout, Frank F., and Soper, E. K., Preliminary R eport on the Clays and Shales of Minnesota, Minn. Geol. Survey, Bull. II, p. 18, 1914. Parmelee, C. W., Further Inv estigation of Illinois Fire Clays, Bull. 38, Ill. Geol. Survey, p . 10, 1921. 2Ries, H., Clays, Their Occurrence, Propertie s and Uses, p. 27, 1908. 

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70 FLORIDA GEOLOGICAL SURVEY-15TH ANNUAL REPORT C. Transported clays. I. Deposited in water. . (a) Marine clays or shales. Deposi . ts of great extent. White-burnipg clays. Ball clays. Fire-clays or shales. Buff-burning. Impure clays or shales { NCalcare1ous. on-ca careous. (b) Lacustrine clays. (Deposited in lakes or swamps.) Fire-clays or shales. Impure clays or shales, red-burning. Calcareous clays, usually of surface character. (c) Flood-plain clays. Usually impure and sandy. (d) Estuarine clays. (Deposite d in estuaries.) Mostly impure and finely laminated. II. Glacial clays, found in the drift, and often stony. May be either red or cream-burning. . III. Wind-formed deposits. (Some loess.) IV. Chemical deposits. (Some flint clays.) (a) Replacement deposits. (b) Chemical deposits. Grout and Soper1 have u sed the phys i cal properties as a ba s is of classification and refractorine ss the basis of su bdivi s ion. It i s as follows: I. (above cone 27). . . U .res. (a) Earthy, usu _ a ll y r esidua l, non-plastic ....... ............. China clay. (b) Plastic ................................................ .Ball clay. (c) Flint-like, non-plastic ...................................... Fire clay. II. Semi-refractory (above cone 10). (a) Safely vitrifying. . f Sewer Pipe. Red burnmg l Paving Brick. Buff or Cream-burning ................................ S 'toneware . (b) Rapidly fusing ................................ Low-grade fire clay. III. Non-refractory (below cone 10). . . . (a) Safely vitrifying. d . { Drain tile. Re -burmng Foundation brick. . { Vitrified brick. Buff or cream-burnmg .............. . F t ' d b k , oun am an sewer nc . . (b) Rapidly fusing ...................................... Common brick. Note-Subdiv!sions of II and III may. be made on the basis of degree of plasticity, or some other physical character. , Recently Pannelee2 has proposed a classification wh i ch is based on the use s of clays according to their physical properties. Parmelee points lGrout, Fran k F., and Soper, E. K., Preliminary Report on the Clays and Shales of Minnesota, Minn. Geol. Survey, Bull. 11, p. 18, 1914. 2Parme lee, C. W., Further Inves tigation of Illinois Fire C l ay, Bu II. 38, Ill. Geol. Survey, p. 10, 1921. 

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A PRELIMINARY ON CLAYS O:F :FLORIDA 71 out that this treats only the uses of clays for burned prod ucts and such other .uses, as paper and cloth filler, pigments, manufac ture of Portland cement, etc., are not considered. He further states that: "This does not exclude clays _ from uses not specified. For example, a superior fire clay may be suited for the manufacture of common brick. Its primary usefulness, however, tnay be regarded as for fire brick since it will be most valuable manufactured into that product." Pannelee1 states that a revised form of this classification is to ap pear in an early of the Journal of the American Ceramic Society, and the classification as first published will, therefore, not be quoted here. !Parmelee, C. W., private communication. CHAPTER III MINERALOGY AND CHEMICAL PROPERTIES OF CLAYS _ .... ,'9-,. I • -." ---'--MINERALS IN UNBURNED CLAYS Clay is composed essen.tially of a hydrous aluminum silicate, in the form of kaolinite perhaps some of the minerals closely re lated to it, varying amounts of colloidal matter, of either organic or min eral character, and fragtnents of a great many different rep resenting chemically oxides, carbonates, silicates, hydroxides, etc. It will be seen then that clays may vary widely in their mineral and chemi cal c<;>mpositions. Kaoli _ nite _ was formerly believed to be the basis of all clay, but this view is now known to be erroneous. It is, however, very abundant in many clays . In one hundred and twelve sampfes of unburned clay ex amined miroscopically by Somers1 he reports kaolinite as in only fourteen. It is a hydrous aluminum silicate represented by the formula Al20a, 2Si02, and is composed then of 46.3 per cent silica ( Si02), 39.8 per cent alumina (Al20a), and 13.9 per cent water (H20). It is insolu ble in hydrochloric acid and slowly soluble in hot sulphuric acid. It is always a secondary product and results from the alteration of other 1Somers, R . E., Microscopic Study of Clays, in U. S. Geol. Survey Bull. 708, p. 292, 1922. 

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{2 FLORIDA GEOLOGICAL SURVEY-15TH ANNUAL REPORT aluminous silicates, feldspar. It is white in color, slightly plastic, has a of 2-2.5 and a specific gravity of 2.2-2.6 . Crystals of kaolinite are of very rare occurrence in clays but have been described by several writers.2 According to I-Iickling3 the kaolinite occurs in irregularly pristns with rough faces which show transverse striati ons that correspond . to the basal cleavage. There are several ntinerals very closely related to kaolinite. These are all hydrous alun1inum silicates, but it is doubtful if all comtnonly placed in this class are. really distinct species. They son1et imes occur in crys talline form, but more frequently occur in the an1orphous condi tion. These tninerals are halloysite, indianaite, pholerite, recto rite, new tonite, ailophane , cin1olite, n1onttnorillonite, pyrophyllite, collyrite , and Some of these minerals can be identified by their optical properties.1 There are many other minerals not related to kaolinite which are often found in clays and do not decotnpose readily. They may be briefly treated as follows : Quart z-Si02. This mineral is fou . nd in practically every clay, though usually in very fine grains and s on1etime s in very stnall quantities. It m ay also occur in the amorphous form. In residual clays the grains are usually angular while in the sedimentary clays they are somewhat due to the rolling and tossing about they have rec eived by the water action. In quantity in clays quartz ranges from Ies . s than one per cent . in some white sedimentary clays to more than eighty per cent in some other clays. Quartz fuses at 1830 o C. (cone 35) ,2 but in the presence of other mi:perals act as a flux it n1ay soften at a lower temperature. In clays it affects the .fusibility, plasticity, and bonding strength, depending upon the and texture of the quartz present. M., Mining Magazine, Vol. VIII, P. 15, 1876. Reusch, H., Jahrb. f. Min., Vol. II, p. 70, 1887 . Johnson, S. W., and Blake, J. M., American Journal of Science, II, Vol. XLIII, p. 351. 1867. . . . 3Hickling, G., China Clay; Its Nature and Origin, Trans. Inst. Min. Eng. (England), Vol. 36, 1908-9. . lLarsen, E. S., The Microscopic Determination of the Non-opaque Minerals, U. S. Geol. Survey Bull. 679, 1921. 2Ries, H., Clays, Their Occurrence, Properties and Uses, p. 55, 1908. 

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A PRELIMINARY REPORT ON CLAYS OF FLORIDA 73 Fe!dspar-This mineral.as a rule is not abundant in clays, though it more readily than quartz and usually occurs in smaller grains. Feldspar occurs in several forms which differ slightly in their chemical cotnpositions. \Vhile these different species of feldspar vary to some extent in their tnelting points it may be said that feldspar fuses at about i310 c. (cone 9 although in the presence of alkalies this tetnperature is tnuch lower : Ciarke4 gives the n1elting point of feldspar as ranging from 12 . 65 to 1550 C. He points out, however, that these obs . ervations were tnade upon artificial preparations of great purity. COMPOSI'I'ION OF FELDSPARS1 Chemiclll Composition Feldspar Species I Si02 Al20a l K20 ( Na20 I I CaO Orthoclase ..................... 64.70 18.40 1"6.90 0.00 I 0.00 Albite . . . . ... ............ ...... 68 . 00 20.00 00.00 12.00 I 12.89 Oligoclase ..................... 62.00 24.00 00.00 9.00 5.00 Labradorite ................... . 53.00 30.00 00.00 4.00 I 13.00 Anorthite ....... .. ........ ... . 43.00 37 . 00 00.00 0.00 20 . 00 l \111:ca-This is another tni neral which occurs in the form of several different . species \.vhich likewise . have a variation in their different cornpostttons. occurs in n1ost clays anq is very difficult to remove . . In \vashing, on account of its light scaly character, it floats off with the clay particles. 1\llica acts as a flux in clays at a high tetnpera It is abundant in th . e clays of Florida. Few clays of the State are free from it, while in son1e of those in the western . counties it is present . in large quantities . The chief tnica is tnuscovite because it is less easily weathered. Hydro1nica-Hydron1ica is, according to Son1ers2 a distinctly tnica ceous n1ineral which represents a transition stage of weathering between sericite and kaolinite, with kaolinite as the final product. Somers reports hydrom-ica as scarce in only tvventy-t\vo and unidentifiable in t:welve of the clays exan1ined by hiin. Hydrotnica is peculiarly abundant in many clays. H., Clays, Their Occurrence, Propertie. s and Uses, p. 55, 1908 . 4C!arke, F . W., Data U. S . Geol. Survey Bull. 695, p. 360, 1920. 1Rtes, H., Clays, Theu Occurrence, Properties and Uses, p. 55, 1908. 2 Somers, R. E., Microscopic Study of Clays, in U. S. Geol. Survey, Bull. 708, p. 296, 1922. 

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74 FLORIDA GEOLOGICAL SURVEY-15TH ANNUAL REPORT Limonite-This is an iron mineral represented by the formula 2Fe20s, BH20 . Its occurrence in clays is widespread and iri a variety of forms. When present in a finely divided state it gives to the clay a yellowish or brownish color. It al ways a secondary product resulting frotn the alteration of other minerals. It may occur in clays in fine grains, as a coating or thin film covering the clay particles, as concretions, or limonitic crusts and layers . It exerts a strong coloring and fluxing in the burning process, if abundant and uniformly The pre s en::-e of a very small per cent may produce a notice able coloring effect and i s therefore an injurious ingredient of a clay desired for whiteware . If limonite occurs in small lumps and these are not finely crushed, they appear in the burned product as unsightly black splot(:hes. Limonite concretions are very common in many Florida c}ays and limonite or other hydrous iron oxides in other forms is widely dis tributed over the State. H This is another iron mineral which may be found in clays, but as it alters to limonite easily on being exposed to moisture and air, it i s not so common. Its effect in cla ys is similar to that of limonite. M agnetite-Fes04. A magnetic ore found in some clays as black magnetic grains. It i s not, however, a cotnmon constituent of . clays. Siderit e-FeCOs . This is the iron carbonate which occurs in some c . lays and shales as concretionary masses or as disseminations. It changes to limonite if e . xposed to the weathering agencies. If in a divided state and evenly distributed through the clay, it is said to give a blue or slate-gray color to the raw clay . In burning the carbon dioxide, ( C02), is driven off. The resulting effect is probably similar to that of limonite. Pyrite-F eS2. This mineral, the iron sulphide, is common in some clays and was noted in som e of the Florida clays. It is pale or brassy yellow in color, has a metallic; lu s tre, and occurs as small cubical grains or as nodular lumps. Pyrite is an injurious ingredient as it. not only has an effect sitnilar to that of the other iron . minerals but the sulphur dioxide ( S02) m ay, in burning, unite with steam to form sulphuric acid (H2S04), which in turn may combine with calcitun or _ magne sium corn pounds to form soluble salts . These may cause a white effloresence or coating on the If the p y rite occurs in large n1asses it n1ay be screened or picked out by hand. Pyrite is an impurity in coal 

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A PRELIMINARY REPOR'f ON CLAYS OF FLORIDA 75 and when such coal is u se d as fuel in firing clay products it'may cause th. e same injurious scumming effects as when it is an ingredient of the clay. Calcit e-CaCOa. The presence of this mineral in clays can be easily detected by the application of a few drops of hydrochloric acid which . . causes the to efferve sc e briskly . . Calcite is quite abundant in son1e clays and ma y occur as disseminations, as concretions, or as fragments of lirpestone. Thes e larger pieces can be separated by h a nd in minin g . Calcite acts as a flux in b1:1rning and if present in fine lump s is converted into ( CaO) which s lakes upon being exposed to air and the ware to crumble unless If tr.e calcite is pre sen t in a finely divided and evenly distributed through the clay it has no especial injuriou s effect. Sotpe . of the Florida cla ys are quite calcareous. At higher ternperatures the lime resulting from the burning of calcite will unite \Vith the other elements of the clay , especiall y the alumina a:1d s ilica, giving a reaction which has a marked . effect on the color as well as the fusibility of the clay. If the lime be in excess of the iron, when iron i s presen t, it has a tendenc y to give the wa re a buff color. Ries1 states that this effect is most marked when the percentage of lime is three times thatof iron. 2H20 . This mineral , the calcium sulphate, is not widely distributed in clays, but in some depo s its it occurs abundantly. . ' It is regarded as an injurious ingredi ent w hen ptesent. Ries2 says: ' .'The effect of gypsum on clay is that of a flux, especially if the brick is burned to vitrification, but if the clay is not burned sufficiently hard to drive off the sulphuric which the gypsum contains combined with the lime, then soluble sulphates may be left in the clay, which will be brought to the s urface of the brick where they cause an unsightly white coating upon evaporation of the moi sture." Gypsun1 has a pearly lustre and occurs in plate-like crysta l s or in fibrous forll? and exhibits no efferve s cence when acid is applied. It n1ay be secondary in origin in clays and is formed by the action of sulphuric acid . upon calcium carbonate. Gypsum specks in burned clay do not cau s e the ware to slake as is the case when calcite is pres ent. Ries3 s tates that he has lRies, fl., Clays, Their Occurren ce, Properties and Uses, p. 87, 1908. 2Ries, H., Clays of Maryland, Md. Geol. Survey, Special Publication, Vol. IV, Part III, p. 225, 1902. 3 Ries, H., Private .Communication. 

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76 FLORIDA GEOLOGICAL SURVEY-15'rH ANNUAL REPORT collected clays in Florida that had crystals of selenite .(one form of gypsum) as much as a half an inch in diatneter. Rutile-Ti02. This mineral is probably widely distributed in usually in small amounts. Few atten1pts have been made to identify it in clays. It rarely occurs in large quantities. Sotners4 reports rutile as unidentifiable in three of the one hundred and twelve clays examined miroscopically by hin1, n1oderate in three, scar.<;e in fifty-three, comn1on in twenty, and abundant in thirty-three. Its effect is negligible except in white-burning clays . It usually occurs in tnicroscopic grains. Ilm enite-TiFe20a. It is not definitely known that this mineral occurs in clays, but its occurrence is probable in those clays which have been derived from soda-rich and basic eruptive rocks. Ihnenite is a constituent of sonle of the sands along the east coast of Florida and its presence is to be expected in son1e of the clays of that region. effect is perhaps sitnilar to that of rutile. Glauconite-This tnineral, often called is a hydrated silicate of ferric iron and potassium with alun1inum and water in vari able proportions, and usually tnixed with other minerals. It is easily fusible and hence a high percentage of it is not desirable. It is olive to grayish-green in color. It occurs in tnany of the chtys of the Atlantic coastal plain region and has been reported in cia ys in New J er s e y1 , Maryland2 , Georgia3 • Chlorite-This is applied to a group of secondary minerals which are hydrous alt11ninutn silicates with ferrous iron and magnesium. Ferric iron may son1etin1es be present. It is found in stnall quantities in son1e clays. Its presence in the. Cretaceous cla ys of Georgia4 and the Leda clays of Canada5 has been reported. Dul"o11 t,:ile-Cal\1g ( C03) 2. D olon1i te i s very sitnilar in conlposi tion and properties to calcite. Alone it is highly refractory, but acts as a flux with other tnineral s. Dolon1.ite is con1n1on in son1e of the clays of the Manatee River region. 4Somers, R. E., Microscopic Study of. Clays, in U . S. Geol. Survey Bull. 708, p. 292, 1922. lNew Jersey Geol. Survey, I Report, VI, p . 46, 1904. 2Maryland Geol. Survey, Eocene, p. 52, 1901. 3Veatch, Otto, Clay Deposits of Georgia, Georgia. Geol. Survey, Bull. 18, p. 41, 1909. 4Ladd, G. E., American Geologist, Vol. XXIII, p . 240, 1899. 5Merri11, G . P . , Rocks, Rock Weathering, and Soils, p. 335, 1913 . 

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A PRELIMINARY REPORT ON CLAYS OF FLORIDA 77 Hornblende-This is a complex silicate frequently found in some in1pure clays. It weathers readily and colors the clay red, O\ving prob ably to its iron content. Garnet-This is another con1plex silicate, \vhich occurs as grains in some impure clays. Its is sitnilar to that of hornblende. 8H20 . . A hydrous phosphate which inay occur in sotne clays. it is not a cotnn1on constituent of clays, bu. t _ occurs in sotne Atlantic coast clays as stnall blue spots. Its presence in large quantities has not been determined. Pjwolusite-Mn02 ( Psi!o11te lane-H4Mn0;:;) These n1anganese oxide s are usually secondary in origin and occur frequently in residual clays, but they are not, however, of very widespread distribution. Iri clays they rarely exceed one per cent. They exert a coloring effect sin1ilar to that of iron and are often the coloring agen . ts on those clays used in tnineral paint or pigments. MINERALS. IN BURNEJ? CLAY Very few attempts been n1ade to study the minerals in burned clay. Porcelain and some other types of high-grade products have been studied microscopically to some extent, but only about six investi gators1 seem to have carried on. any experin1ents on clay alone. Son1ers apparently did the n1ost _ exhaustive work so far atten1pted on An1erican clays. , Somers' work shows that qtiartz usually stands out with mtJch greater. clearness in the bur.n ed than the raw ..clay. He states that in a few cases a fluxing action appears to have taken place between the finegrained n1aterial and the silica. , . . . 1Vernadsky, W., Soc . franc, mineralogie Bull., Vol. 13, p. 256, 1890 . Glasenapp, M., Ueber Aenderungen der .Mikostruktur der Tone durch "Ein wirkung hoher Hitzegrade: Tonind. ustrie Vol. . 31, p. 1167, 1907. Klein, A. A., The Constitution and Microstructure of Porcelain: American . Ceramic Soc. Trans., Vol. 18, p. 377, 1916. Mellor, J. W . , Can the firing temperature of a body be determined from the . microscopic appearance?: Eng. Ceramic Soc. Trans. , Vol. 16, pt. 1, p. 71, 1917. . . Somers, R. E., Microscoprc Study of Clays, U . S'. Geol. Survey, Bull. 709, p. 300; 1922. Schurecht, H. G., The Microscop i c Examination of the Mineral Constituents of some American Kaolins, Jour. of Am. Ceramic Society, Vol. 5, p. 3, 1922. 

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78 . FLORIDA GEOLOGICAL SURVEY-15TH ANNUAL REPORT Hydromica, as the results of the same investigator show, either practically disappears at 1150 C. or lose s the greater part of its inter ference color. Son1ers states that: "This change of the hydromica on heating suggests that it furnishes some of the flux for the clay, and other things being equal, there 1nay be a connection between the degree of density at the temperature mentioll:ed . and the quantity of hydron1ica present." Somers . further states that: "If it is not fluxed, kaolinite appears to retain its shape and at least a part of its original interference color. Tourmaline and probably epidote disappear even at 1150 C., but rutile, zircon, and probably titanite seem to be unaffected even at 1300 C." A white Florida day fired at 1150 . C. exhibited the formation of sillimanite. Somers believed it to have forn1ed fr01n large flakes of kaolinite or the low-grade hydromica . Other sitni lar clays treated in the same manner did not develop sillimanite. THE CHEMICAL ANALYSIS OF CLAYS . . . There are in common usage two methods of clay analysis. One of these is known as the ultimate analysis and the other as the rational analysis. The ultin1ate analysis is the one most frequently used. It is the one which considers the various ingredients of a clay as oxides, yet their exact condition may be in much more forms. Calcium . car-. . bonate ( CaCOs) is thus considered as being broken up into carbon dioxide ( C02) and lime ( CaO), with the percentage of each given separ ately. The sum of these two percentages would, on the other hand, be equal to the amount of calcium carbonate in .the clay. The common method of expressing the ultimate analysis of-a clay is as follows: Silica ........................ . Alumina .................... . Ferric Oxide ..... ......•..•.• Ferrous Oxide ............... . Lime ....................... . Magnesia ................... . Fluxing Impurities. Potash ...................... . Soda ........................ . Titanic acid .................• Sulphur trioxide ............. . Carbon dioxide .............. . Water ... . . . . ........ ...... . Organic matter .............. . 

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A PRELIMINARY REPORT ON CLAYS OF FLORIDA 79 The ultimate analysis does not indicate what compounds are present in a clay, but at the same time sotne data can be derived frotn it. Ries1 lists the following facts as obtainable from chen1ical analysis: "1. The purity of the clay, showing the proportions of silica, alumi na, combined water and fluxing impurities present. High-grade_ clays often show a percentage of silica, alumina, and chemically combined water approaching quite closely to kaolinite. 2. The approximate refractoriness of a clay; for other things being equal, a clay with high total fluxes, is commonly less refractory than one with low total fluxes. In this . connection it is to be remembered texture, irregularity of distribution of the constituent . s, and condition of kiln atmosphere are among conditions affecting the result. 3. The color to which the clay burns. This must be judged with caution. Assuming constituents to be evenly distributed, then a clay with 1 per cent or less of ferric oxide is likely to burn white, but at temperatures titanium if present produces discoloration. One with 2-3 per cent of ferric oxide is likely to bu'rn buff; one with several per cent or more of ferric oxide will usually burn red if there is no excess of lime or alumina: It should be remembered that condition of ' the kiln atmosphere, texture of the clay, and sulphur in the fire gas may all affect the results. 4. The quantity of chemically combined water. Clays with a large amount sometimes show a high shrinkage, but there are many excep tions to this . . 5. Excess of silica. A high percentage of silica ( 80-90 per cent) may indicate a sandy clay, and possibly one of low shrinkage, but does not necessarily point to a very lean one. High silica in a fire clay usually shows only moderate refractoriness provided it is evenly distributed . 6. Organic II!atter. This should be determined, a s it causes trouble in burning if present to the extent of several per cent, requiring thorough oxidation in firing before the clay is allowed to pass to the vitrification stage . . 7. Sulphur trioxide. Since this may be the cause of swelling in im properly burned wares, and also indicate the presence of soluble sul phates, it sqould always be determined. lRies, H., Clays, Their Occurrence, Properties and Uses, p. 62, 1908. New Jersey Final Report, Vol. VI, p. 50, 1904. 

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80 FLORIDA GEOLOGICAL SURVEY-15TH ANNUAL REPORT 8. The presence of severa l per cent of lin1e and carbon dioxide shows the cla y to be of calcareous characte r , and n ot on l y ofte n of bt1ffbuming character but with a narrow n1argin between vitrification and viscosity . 9. Titanium oxide should be detern1ined, e spec ially in fire clays , as a small quantit y nlay redu ce the fusion point of fire clay s everal cone s . 0 0 It might be seen fion1 the above that the ultin1at e an?lysis yields u s much, and yet 1t leaves u s practically in the dark as to the plasticity, air and fire shrinkage, den sity and hardnes s of burning, ten s ile strength, etc." In modern clay investigation en1phasis i s placed on the physical 0 0 tests and the ultimate analysis is rarely made because it is of little praCtical value except in rare ca s es. The rational analysis atten1pts to re so lve the clay into its constituent minerals , and in one sense of the word gives a n1ore accurate con ception of the true of the n1aterial. The ordinary analysis divides the clay into: clay :5ubstance, quartz, and feldspar. The n1ethod as at present used is not by any tneans sa tisfactory, nor is it altogether safe to figure the mineral con1position fron1 the ultin1ate analysis.1 . Methods of makin g both th e ultitnate and rati o nal analy,sis are conveniently outlined in a of publications dealing with clays and clay technolog y .2 CHEMICAL EFFEC'I' Ol" VARIOUS CONS'l'l'l'UENTS I N CLAYS Silica--Silica may occur in a cla y in the free state as quartz or it may occur in a combined state in the forn1 of the silicate n1inerals. The common silicate u1inerals f o und in clays are kaolinite, hydromicas, feldspar, mica, hornblende, etc . The total silica is usuall y given in . the ultimate analysis and include s both the free and the con1bined forn1s. Except in the case of kaolinite the silicate tninerals occur in a more or less sandy condition and exer t an inA uence upon the plasticity and shrinkage as does quartz. A ll of these affect the fire shrinkage and fu s ibility . of the !Washington, H. S., The Calculation of the " Rational .Analysis" of Clays, Jour. Am. Ceramic Society. VoL I, p. 405, 1918. 2Washington, H. S., Manual of the Chemical Analys!s of Rocks, 1919. . Hillebrand, W. F . , The Analysis of Silicate . and Carbonate Rocks, U. S. Geol. Survey Bull. 700, 1919. Hillebrand, W. F., Some Principles and Methods of Rock . Analysis, U. S . . Geol. Survey Bull. 176, 1900. . 

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A PRELIMINARY REPORT ON CLAYS OF FLORIDA clay. Indeed, sand Js often added to sotne brick clays having a s hrinkage in order. to reduce the shrinkage. Contrary to the belief of some, the addition of quartz does not the ft;sion point of a clay. Quartz alone is very refractory, but in pres ence of highl y aluminous l ow-flux cla ys it s refractoriness is duced. A high percentage of si li ca for a very refractory clay is a6t desirable. rf . n is one of the comtn on constituents of all cla hs and i s derived not only from kaolinite but n1any of the othe r si lic ates (lS \veiL Alone it i s highly refractory, but in the pre se nce of fluxes its fusion point is l owe red. . Iron Oxide-This both the ferric oxide, Fez03 , and tHe ferrous oxide, FeO. The I iron oxides in clay are derived frotn iron minerals as limonite , hetnatite , pyrite, s id e rite, and also from s ucb siHca tes as mica, hornblende , garnet, glauconite, etc. ts Iron acts as a stron g coloring agent in both the burned and un burned clay. Its range of color influenc . e is from a very faint creaiPl, through yellow and buff, to all shades of red, brown, and blue to blactt The res ulting color, however, i s not so lel y detern1ined by the quantify of iron ox. ide pre sent but also by the texture and dis tribution in the ctctf, the forn1 of the ' iron, whether ferric or ferrous, condition of the klfh atmosphere, whether oxidizing or reducing, the neutralization of other con s tituents as lime. . ) l The iron oxides likewi se exert a strong fluxing action, thus ing the fusion point of the cl ay. Ries1 . states that "this effect will Be more pronounced if the iron i s in a ferrous condition or if silica 1s pre s ent." The iron oxide probably enters into combination '"' ith s ilica , forming an easily fusible si lic a te. Iron may therefore be either a desirable or an unde s irable ingredie n t of. clays. In the lower grades of ware its coloring and fluxing action is be . neficial. The flu x ing action reduces the temperature at which burning must be done. In other wa res, such as white wares and refractory protf ucts, it is detritnental. It i s obvious tha t in white-burning cla ys the ir6h content must be very low. q d . }l lRies, H., Clays, Their Occurrence, Properties and Uses, p. 85, 1908. 

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82 FLORIDA GEOLOGICAL SURVEY-I 5TH ANNUAL REPORT L ime-Lime is found in one form or another in many clays, but all form s may be classed as .car bonate s, silicates, or su lphat es. Calcite, or to a le sse r extent is the usual source of lime carbonate, gypsum is u s ually the source of the su lph ate. Some si licate s such as some of the feldspars and may contain lime in combination, but the lime con tent of such silicates i s u s u ally quite low, and they therefore s upply but little. When lime is present in the form of the carbonate, ( CaCOs), it may be by the application of an acid, as or nitric, which will react with the carbonate to produce an effervescence due to the escape of the carbon dioxide, ( C02). When in the form of the carbonate, lime i s the most effective. If in a finely divided state it acts as a flux. When not in a finely divided state the carbonate changes to quicklime on burnin g with the l oss of the carbon dioxide gas. The quicklime later take s up moisture from the atmosphere and slakes with accompanying swe lling or crumbling. Ries1 states that: "If the temperature is rai s ed higher than is re quired simply to drive off the carbon dioxide, and if some of the min eral particles soften, a chemical reaction begins between the lime, iron, and some of the silica and alumina of the clay, the result being the forma tion within the clay of a new si licate of very complex composition. The effects of this combination are several : In the fir st place the lime tend s to destroy the red coloring of the iron and impart s instead a buff color to the burned clay. This bleaching action is most. mat; ked when the percentage of lime is three times that of iron. It shou ld be remembered , however, that all buff-burning cla ys are not ca lcareous , and that a clay containing a low percentage of iron oxide may also give a buff body. Another effect of lime, if present in sufficient quantity, i s to cause the clay to soften rapidl y, thereb y sqmetimes drawing the points of incipient fu s ion and viscosity clo se together and giving what i s termed a short firing range. This rapid softening of the calcareous cla ys i s one of the main objections to their u se, and on thi s account also it i s not usually safe to attempt the manufacture of vitrified products from them, but the presence of several per cent of magnesia will counteract thi s. It has a l so been found po ss ible to increa se the interval the points of incip ient "fusion and visco s ity by the addition of quartz and feldspar." lRies, H., Clays, Their Occurrence, Properties and Uses, p. 87, 1908. 

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A PRELIMINARY REPORT ON CLAYS OF FLORIDA 83 It is believed by many that a highly calcareous clay is entirely undes irable. This, however, i s not a lways the case. Wis con s in cla y s2 , highly calcareous, . a good building brick. When a vitrified ware is not attetnpted and the lime is in a finely div:ided and evenly distributed state, a good clay may contain as much as 20 to 25 per cent. It is interesting to note that the calcareous Wisconsin clays u se d in the manufacture of brick, are burned, with a few exception s, at a much hi gher temperature tha n _ the n o n-calcare o u s ones1 • The lime contained in the silicates have no noticeable detrimental or beneficial effects. While they may act a s fluxes, they do not cause the ware to soften rapidly. When lime i s present in the form_ of the sulphate it will, when heated sufficiently high, be broken up into calcium oxide, ( CaO), and sulphur trioxide, (SO a) . The sulphur trioxide may cause blister s or cracks in the ware as it escapes. M agnesiv-Magnesia may occur in the same form a s lime, but the s ilicate s in this case a re the r . n .ost in1portant sources . In this form it acts in much the same manner as calcium silicate, but is not quite so active . While magnesia acts as a flux in firing it doe s not caus e the clay to soften as rapidly as calcium and the points of incipient fus ion and viscosity are more widel y separated. Magnesium-bearing minerals which might occur in clays are biotite (black rnica), hornblende, chlorite, dol<?mite, etc. The cl1lorite may be abundant in some partially decom po s ed res idual clays and .the dol01nite in sotne sedimentary ones . . Alkalies-This term is u sed to inch.ide potash soda (NazO), ammonia (NI-ls). Ammonia is present in some raw clay, but as it i s easil y vo latile it readily escape s when the ware is heated. Soda and potash, called the ' fixed alkalies, are present in almos t every c lay. The complex s ilicate s, a s n1ica , green s and, orthoclas e, etc., are the principal sou rces of the alkalie s i'n clays. Some alka li carbonate may be held in clay by adsorption. They are regarded as the most active fluxe s present in clays. Except in the case of clays,' they are des irable constituents when in the fonn of By their fluxing action they bind the clay particles together in a dense hard body at a lower temperature than would otherwise be poss ibl e. It is for this reason that feld spar is used as a flux in many high-grade wares. There i s practically no coloring effect exerted by the alkalies. 2Clays of Wisconsin, Wisconsin Geological Survey, Bull. XV, p. 18, 1906. . lClays of Wisconsin, Wis. Geol. Survey, Bull. 15, p . 36, 1906. 

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84 FLORIDA GEOLOGICAL SURVEY-I 5TH ANNUAL REPORT Titanium-Titanium is often regarded as an uncommon cqnstituen t of clays but in reality it is of frequent occurrence. Rutile and ilmenite are the most important sources of titanium dioxide in clays. Unfortunately tests for titanium are rarely in a chemical analysis. It exerts a blue and yellow coloring effect and has shown that it lowers . th e refractoriness of clay. Veatch2 states that titanium was shown in the of some Georgia clays, but when those clays were exan1ined microscopically no titaniun1 minerals could be identified with certainty. Water-This includes the mechanically con1bined water or moisture and the chen1ically con1bined water. The n1echanically combined water is that held in the spaces between the clay particles by capillary action and can be driven off by heating the clay to the boiling point of water. The _loss of this water causes the clay -to shrink to a extent. This shrinkage, known as air shrinkage, ceases when the clay particles have all cotne in contact. The chemically combined water exists in con1bina tion with other elements and can only be driven off at a temperature ranging from 400 o to 600 o C. _ Organic Matter-Organic matter, usually in the form of particles, occurs in many .clays . It is a strong coloring agent in the un burned state and itnparts to the clay a gray, blue, brown or black color. The same clays may, on burning, be red, buff, cream, or white , depending upon the. other coloring agents. In such cases the carbonaceous matter has masked the other substances like iron in the raw state. Carbon may interfere with the proper oxida-tion qf iron and expul sion of sulphur when Clays with a high content of organic mat-ter are of common occurrence in Florida. ' . It has been shown by the experiments of Orton and. Griffin3 that between 800 and 900 C. is the best tetnperature interval for burning off the carbon, as this the oxidation of it dqes not proceed as rapidly, and above this there is danger of vitrification beginning and the oxidation being stopped. All the should first be driven out of the clay, then the heat raised as rapidly as possible to. a temperature between 800 and 900 C. held there until the ware no longer shows a black core denoting ferrous iron. lRies; H . , Clays, Their Occurrence, Properties and Uses, p. 104, 1908. 2Veatch, Otto, Clay Deposits of Georgia, Georgia Geol. Bull. 18, p. 48, 1909. 3Second Report of Commi"ttee on Technical Investigation, National Brick Makers' Association, Indianapolis, 1905. 

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A PRELIMINARY REPORT ON CLAYS OF FLORIDA 85 Sulphur-The detei-tnination of sulphur is rarely made in the analy sis of a clay unless it is being considered for the n1anufacture of Portland cement. It son1etin1es occurs, however, in clays and when present is usually in the fonn of sulphate or s ulphide. Orton and Staley1 con cluded, frotn a series of experiments carried on by them, that sulphur retained in the clay during the period of burning, regardless of its form or cause of retention, is not likely to cause any physical disturbance until a fairly complete degree of vitrification is reached, but when a dense vitrified state is reached it soon becomes less dense, on account of the fonnation of multitudes of tninute vesicles in the viscous body, and finally the body becotnes _spongy and worthless. They further conclude: "That in clays of low sulphur content, and of favorable structure for oxidation, the amount of sulphur left in the clay at vitrification is very sn1all. Hence the period of good structure is long, the vesicular structure deyelops slowly, and the clay is said to stand overfiring well. "In sotne clays of high sulphur content or of dense structure unfavorable for oxidation, or of high content of iron and carbon, the escape of sulphur is prevented, the clay has a narrow period of usefulness, or none at all, and the vesicular structure becon1es enortnously exag gerated." Soluble Salts-Soluble salts is a tern1 applied to those readily soluble in water. which are found in practically all clays to a greater or less degree. Upon being dried the tnoisture in the clay carries these cotnpound s to the surface where it leaves them, upon evaporation, as an efflorescence. This or white coating tnay also occur in the burned product to moisture. The ternT ueffioresence" and "sctun" have hitherto been used inter to describe the accumulatiot1 of the salts (coating) upon the surface where they have been brought in solution and deposited upon the evaporation of the water. Pannelee2 suggests that the usage of the tern1 effioresence be limited only to include those surface deposits of salts that accumulate on raw clays in their original beds or in storage bins; all those surface deposits which occur in the drying of the ware, 1Third Report of Committee on Technical Investigation National Brick Makers' Association, Indianapolis, 1908. ' . 2Parmelee, C. W., Soluble Salts and Clay Wares, an address before the IndianaIllinois Division of the American Face Brick Association. Chicago, April 11, 1922. 

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86 FLORIDA GEOLOGICAL SURVEY-I 5TH ANNUAL REPORT except those ca ses where the ware is dried b y the waste heat from burning kilns; all coating s of soluble s alts in ma s onry work in walks, piers, etc . , which have originated t4rough the solvent action of water upon n1aterial s in the cla y wa r es o r has been contributed b y the n1ortar used; and tho s e coatings of soluble salts brought to the s urface during the early s ta g e of burnin g (water-smo king period). He also suggests that the term sc um be limited to de s ignate all tho s e surface c . oatings of soluble s alt s which have originated through depo s its upon the surface of vola tile substances. This distinction is adhered to in the following discus sion of s oluble s alts : Soluble salts brought out in the drying. of the ware are termed "dryer white," those appearing in the process of burning are "kiln white," and those which come to the s urface of the fini s hed product after being exposed to moisture "wall white". While soluble salts are pre s ent in all cla ys they may occur in various forms and may res ult frotn several cau ses. Not all of the se , howe v er, are harmful. It al s o so metime s happens that other condition s intervene in behalf of the manufacturer to reduce the harmful effect of the more • objectionable ones. Thes e soluble salts may occur as the hydrated silicic acid, . as aluminum salts, as the sulphates of iron, calcium, magne s ium; sodium, pota ss ium, etc., also as sodium chloride or common sa lt. Some of the compounds of vanadium at times occur a s soluble salts. The calcium and magnesium . sulphates are the most troublesome and incidentally are the one s most frequently found . The soluble salts may be present in the clay in its raw state; they may result from the decompo s ition of certain mineral impurities in the clay a s pyrite, upon expo sure to moi sture and air; they may be introduced by gases coming from fuel u s ed in drying or burning; or they tnay be brought into the clay by the water u s ed in tempering. In any where soluble salts o ccur the water used should be considered. Parn1elee1 ha s pointed out that clay particles are of very t n inu te size and when these are subjected to prolonged contact.with water they are more or le ss taken into s olution . Thus , the same writer adds, the de termination of the amount of the soluble salts in clays is seriously com-lL . OC. Cit. 

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A PRELIMINARY REPORT ON CLAYS OF FLORIDA 87 plicated by the progressive solub ilit y of clay in contact with water, so that the duration of the contact and the temperature are extremely im portant factors. If pyrite i s present in a clay it oxidizes when exposed to air and n1ois ture t o form the so luble ir on su lphate. I ts pre s ence n1ay often be detected by a yellow or brownish-yellow effloresence on the raw clay. It is oxidized during burnin g to red or brown. The iron sulphate decom poses with the formation of su lphuric acid which then attac k s the calci um, magne s ium, or iron compounds to form the sulphates of these ele ments. In some cases organic acids present in many clays m ay attack calcium carbonate (often in the form of to form some of the soluble salt s. The maximum amount of so lubl e salts which may be present in a clay without detrimental results is not known. It is placed by some in vestigators at a s low a s one-tenth of one per cent. Dr. Mac kler1 says : "The amount of scum (efflorescence) formed on finished go'ods bears no definite relation to the proportion of soluble salt s contained, but there is quite a definite relation between the amount of the magnesium and sod ium sulphates and that of scum ( effloresence) . " On this point Staley2 write s "that he added calc iun1 s u lph ate to a fine-grained, red burning shale in amounts increasing to 3 per cent of the dry clay and was unable to produce efflor esence even with slow drying. When he added 1 per cent of magnesium sulphate it appeared in large quantities and a 1 per cent tnixture of parts of the sulphates of calcium and magnesium give an even greater amoun t of effloresence." He ex plains thi s by pointing out that magnesium sulphate is very soluble in water while calciun1 sulphate only a slight so lubility . He also states that calcium sulph ate hastened the rate of drying which would act to ward a decrease in effloresence. There are severa l methods of preventing the troublesome effect of soluble salts . The numerous remedies which . have been suggested and used depend upon the character, origin, and occurrence of the salts in the clay in question. In cases u se of the clay in the unweathered condition i s desirable. In other case s prolonged and thorough weathering will permit the objectionable compounds to be le ached out. Rapid lQuoted in C l ayworkers' Handbook, p. 213, 1906. 2Staley, Homer F., Use of Barium F luoride for the Prevention of Dryer Scum on Bricks. Trans. Am. Ceramic Soc., Vol. XVII, p. 200, 

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88 FLORIDA GEOLOGICAL SURVEY-15TH ANNUAL REPORT firing may prevent the concentration of the salts on the surface of the l}Mck or using a reducing flame in the kiln may counteract the ill effects a'i!times. Coating the ware with some organic substance such as rubber, tar, or flour is often satisfactory. Washing the clay in much the same rlranner as i s followed in the sedin1entary kaolin mines in Lake and Put rufm Counties will usuall y accompli s h the desired result, but this method i s i _somewhat expensive except for high-grade wares. Probably one of most satisfactory methods of prevention is to convert the soluble into insoluble compounds. This can be accomplished b y reactions wfth barium compounds . For example, if a clay containing calcium stllphate i s treated with b arium chloride the insoluble bariutn sulphate and calcium chloride res ults. The calcium chloride is decon1posed in burning without hannful results . There are several ways in which this general method can be applied. -fl : 2 01 91 bJ i n -l bJ 9I rn -} , . nt j:> j=:> b! 2j 1 bi 

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A PRELIMINARY REPORT ON CLAYS OF FLORIDA 89 CHAPTER IV ' PHYSICAL PROPERTIES OF CLAYS Clays possess certain characteristics which are of a physical nature and which are variable in different clays. The value of a clay for the n1anufacture of clay products depends ttpon these physical properties. Hereiti lies the necessitydetermining the possib . ilities and lin1itations of a clay by a series of physical tests . These also determine the kind of product for which the clay is best suited. The more important physical properties will be briefly PLASTICITY Plasticity is one of n10$t in1portant properties of a clay, for without it the manufacture of ordinary clay products would be greatly limited. Plasticity has been defined as the property possessed by a clay of forn1ing a plastic tnass when mixed with water; this definition is satis factory only when applied to clay because plasticity is not a property of clay: alone. Ries1 defines plasticity as "the property which many bodies p<)ssess of changing fonn under pre:;sure, without rupturing, which fonn they retain when the. pressure ceases, it being understood the amount of pressure required, and the degree of possible, wilf vary with the n1aterial." The degree of plasticity varies greatly in different clays . Clays showing a high degree of plasticity are said to be "fat," while those which are only slightly plastic are or "short." .No satisfactory method for measuring plasticity . has as yet been devised. description of the plasticity of a clay is largely a tnatter of individual judgtnent and varies with the personal equation . The of water required to the maximum plasticity in any clay varies with the n1aterial. It ranges froq1 eight or ten per cent in some to over forty per cent in others. The cause of plasticity is thoroughly understood, and while many theories have been a,dvanced to explain it no one of them seem to fit every case. The of. the clay particles has been used in several attempts to explain The fineness of grain theory is that plasticity is due lRies, H., Clays, Their Occurrence, Properties and Uses, p. 119, 1908. 

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90 J!'LORlDA GTSOLOGICAL SURVJtY--;I5TH ANNUAL RE:PORT sol e l y to the finen ess of the c lay particles. Other substances, however, \vhen g-round equall y fine do not have the plasticity that clay has. The plate structur o theo r y i s that cl ay i s n1ade up of very fine plates which affor d pln .. --ti c ity w 'hen n1ix ed with \ Vate r. A U c la ys, however, do not sho\v this platy stntc ture. The int a ,rlockng pa1ticle s theory is that the tiny particles interl ock and thus afford plasticity. A n atten1pt has al s o been rnade to expl ai n by virtue of the presence o f al1uuitut.nt. silicates, tha t i s to say the pla s ticity is due to the hydrou s alun1inun1 s ilicate condition, and that the application of heat drives off the chen1ica ll y cornbined water thus destroying plasticity. The degree o f plasticit), ho\ve ver, does not stand in any relation to the chemical compos ition. Efforts have like, v i s e be e n made to explain . plasticity by molecular attraction and b y the pres ence of colloidal matter. This suppos e s that these colloids take up \vater and thus become jelly-like and plastic. It does not seem likely, in the examination of a series of clays, that any of the theories as yet suggested is the sole cause of plasticity . . It is mor e probabl e that pla s ticity is due to a combination . of them. Some clays are too highly plastic to be handled with maximum facility in the common types of machinery. In such cases a non-plastic substance, as sand, is added to the clay to reduce the plasticity. COLOR The color of a clay is quite variable, ranging from white through gray, yello \v, bro\vn, red to black . Vegetable matter and the nature of the iron compounds present usually determines the color of a .clay, though manganese i s sometim es an important factor. T h e <;olor of the raw clay is not always indicative of the color of the burned product. If the raw clay is red because of the presence of iron compounds , the burned product is likely also to be red. The pres bo'\lreve r, of s ufficient calcium carbonate would tend to neutralize the oolming effect o f the iron and cause a buff or cream color instead. T1l:ne of carbonace ous matter will have little if any, oo tbe ookw of the burned product. It moreover masks the true color of f"alW' The colo r s in burned clays are not as variable as in the raw \V.bite, cream, buff, yellow, and red are the common colors in produm, 

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A PRELIMINARY REPORT ON CLAYS OF FLORIDA 91 TEXTURE The size of grains composing clay varie s from small pebbles to ex tremely minute particles. In fact, these finer particles are. at times • so small as to remain in s u spe n s ion in water an indefinite period. The size of grains, or texture, has an important influence in clays on their plasticity, s hrinkage, porosity, fusibility and strength. Several tnethods of determining the texture of clays are commonly followed, and these are very sitnilar to the methods used in the me chanical analysis of soils.1 SLAKING Sotne clays w hen in1mer sed in water will crumble to a powder in a few minutes, whi le others will at first break up into small masses which s ubsequently crun1ble. This proce ss i s known as slaking; and the test i s usually made by mixing the clay with equal parts of grou nd potter's flint. The tin1e nece ssa ry for a clay to s lake varies from a few minutes in soft porous ones to seve ral days or even weeks in others. A clay which slakes ea s ily can be tempered more readily, and in case of a clay which must be washed, one which slakes readily is more rapidl y disintegrated in process. SHRINKAGE All cla ys exhibit a reduction in size in drying and burning which is tenned shrinkage. The first is the air-shrinkage and the latter is the fire shrinkage. Both fire-and air-shrinkage are com monly measured in two ways, by volume or by linear determinations. The volum . e (or cubic) shrinkage is obtained by determining the volume of the tes t piece when first molded and again after 0rying or burning. The linear shrinkage is measured directly on the ware and expressed in percentage terms of the original length. In clay containing no water the clay particles are all in contact with each other. There are spaces, however, left between the particles. When the clay is brought into contact with water, the se interstitial spaces are filled without the clay changing form. The water necessary to fill these inter s titial spaces js termed the pore water. If additional water is lU. S. Dept. of Agriculture, Bur. of Soils. Bull. 4, p. 9, 1896 . U. S. Dept. of Agriculture, Bur. of Soils. Bull. 64, 1900. 

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92 FLORIDA GEOLOGICAL SURVEY-15TH ANNUAL REPORt added it causes an increase in volume or swelling of the clay. This additional water absorbed by the clay is in the form of a film surrounding each particle of clay. After a clay is mixed yvith water and molded, its water begins to evaporate. As evaporation progresses the particles con1posing the clay cotne again in contact, resulting in a shrinkage of the mass. This will continue until all the wate r fonning a filrn the clay grains has escaped and the clay particles are in contact with each other. This is the point of maximum air-shrinkage if the water lost is the shrinkage water. The only moisture.remaiping in the clay is the por e water which can only be driven off by heating the ware to 100 C. for a few hours. The air-shrinkage in clay s ranges frotn less than one per cent to n1ore than fifteen per cent. Six or seven per cent is about the average. Sand is often added to clays to reduce an exce ssive shrinkage. A ll cla ys shrink to son1e extent during certain stages of the burning process. The fire-shrinkage varies w ithin wide litnits in different clays and ranges frotn one or two per cent in s01ne to n1ore than forty per cent in others. At certain ten1peratures s otne clays may expand to son1e extent. Fire-shrinkage re sults fr01n the driving off of any organic matter present, decon1position of son1e of the chetnica l cotnpounds and the volatilization of cetiain substances as water in the hydrous minerals and carbon dioxide in the carbonate minerals present, etc . . Fire-shrinkage probably begins at the point where chemically . combined waterbegins to pass off and continues, but not uniformly, until the point of vitrification is rea ched, which is the point of maxin1um density. After the expulsion of the vo latile elements the clay is left in a porous condition until the fireshrinkage recotnn1.ence s . Riest, in experimenting with New Jersey clays, found: "That n1ost of the vo l atile sub stances, such as chemically cornbined water contained in the hydrous ahuninun1. si li cates, tnica , or li n1oni te, and organic tnatter, pass off before 500 C . . and that an additio n a l appreciable an1ount is expelled between 500 C. and 600 C . Betvveen 600 C . andllOOo C. ther e was a s n1all but steady l oss. Although the loss in weight between 500 C. and 900 C. is considerable, there is little or no shrinkage, so that after the volatile lRies, H., The Clays and C lay Industry of New Jersey, New Jersey Geol ogica l Survey Report, Vol. VI, p. 94, 1904. 

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A PRELIMINARY REPOR'l' ON CLAYS OF FLORIDA 93 elements have been driven off, the clay tn.ust be very porous, and retnains so until the fire-shrinkage begins again. In these tests, with one ex ception, no shrinkage occurred between 600C. and 900 C., but between 900 C. and 1000 there was a decrease in size and a still greater re duction between 1000 C. and 1100 C. It can be s een fron1 this that up to 600 C. a clay should be heated slowly, btit fron1 that point up t o 1000 C . the tetnperature can be raised quite rapidly-unle ss tnuch carb o n aceous matter is pre se nt. Further heating should be done slowly as the shrinkage recomn1ences at the last-tnentioned tetnperature." In some clays having an excessive fire-shrinkageand where severe losses occur fron1 warping and cracking a substance having no fire shrinkage, a sand or grog (ground bricks, etc.), is often added. Sand, however, may act a s a flux at high tetnperatures. FUSIBILITY All clays fuse or melt at some tetnperature and the ten1perature at which this action takes place is quite variable in different clays. In fact, clays are often classified on the basis of their refractoriness. Every mineral has a definite ten1perature at which it will fuse and this point is usually different for different n1ineral s, but in the case of a n1ixture of n1inerals the point of fusion n1ay be different fron1 that of any mineral in the n1ixture. Thus the fusion point of clay, which is a n1ixture of several minerais, may fuse at a tetnperature fron1 the tnelting point of any of its n1ineral con1ponent s. In such cases the minerals act as a flux on each other. Clays soften slowly clue to different tnineral grains entering into fusion at different temperatures. Ries1 says that in the case . of clays "the tetnperature of fusion de pends on ( 1) the an1ount of fluxes; ( 2) the size of grain of the refractory and non-refractory particles; ( 3) the hon1ogeneity of the mass; ( 4) the condition of the fire, whether oxidizing or reducing; and ( 5) the form of chetnical con1bination of the elen1ents contained in the clay." Three stages are commonly recognized in the heating of a clay to its fusion point. The first is irtC'ipient vitrification, in which there has been sufficient softening to cause the grains to stick together. In this stage the individual grains can no longer be recognized. All the pore spaces, how ever, have not closed. The second stage 'is known as complete vitrifiica-lRies, H., CJays, Their Occurrence, Properties and Uses, p. 166, 

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94 FLORIDA GEOLOGICA L SURV EY-15TH ANNUAL REPORT tion and is accompanied by a sufficient softening of the mass to close all the pore spaces and render the ma s s impervious. The point of maximtun s hrinkage i s als o attain ed in thi s c o nditi on. The s tage o f v iscoHs c a t i on is characterized by further softening or s w elling of th e clay until it flows o r b e cotn es vi s c ous . It is often quite diffi cult to recognize just when these three period _ s have been reached a s the change frotn one to the other i s fr e quently very gradual. In other ca s es the transition is quite s udden. The t etnperature nec ess ary to chan g e a clay from one of thes e condition s to the o ther is dependent upon the compo s ition of the clay and is therefore variable. The difference in temp erature between the points of incipient vitrifi ca tion vi s co s ity may be less than 30 C. in calcareous one s to more than 2 7 5 C. in refractory clays. . In the manufacture of clay products it is not possible to regulate the temperature of the kiln within narrow limits. It therefore becomes necessary to u s e a clay in which the points of incipient vitrification and viscosity are s omewhat s eparated , particularl y if a vitrified ware i s "to be If a clay with a short firing range, as the range in temperature between . incipient vitrifi c ation a n d v i s c os it y i s tern1ed , i s u s e d there i s danger of either not reaching the point of complete vitrification or going too far be y ond this point and melting the cc:>ntents of the kiln . Orton1 ha s ver y di s cu ss ed the nature of the v itrific a ti on process and points out. that "any clay is greatly overloaded with quartz sand, or with large proportions of carbonate of lime, or almost . . any other common mineral . vitrifies with great difficulty, and with a very imperfect degree of vitrification at be s t. It is not only not at all u ncommon in practical work to find clays which will work well for ordinary porous cla y products s uch as building bricks, and s till not vitrify to an ything approxitnating requirement s , but it may fairly be said that there are more cla ys u s ed indu s trially which fall out side of the commerciall y vitrifiable class than fall in it. . The preliminary stages of burning are vitally important in preparing the min erals to combine and fuse into a solid solution. By the time the temperature reache s 900 C. the cotnpound s , (silicates, both h y drous and anhy drous, oxides, hydroxides, carbonate s , sulphides, free .carbon, hydrocarlOrton, Edward Jr., The Legal D e finiti o n of Vitrificati on, T r ans. American Ceramic Society, Vol. XVI, p. 497, 1914. 

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A PRELIMINARY REPORT ON CLAYS OF FLORIDA 95 bons, etc.), derived from the original minerals s hould have been con verted into s table forms, a nd nothing should be left except what may enter into a s ilicate so luti on . The normal beginning of the rea c tion in the vitrification proce ss is from littl e s pot s or foci scattered throughout the body, each focu s being repre se nted by some easily fu sib le mineral grain, or the juxtaposition of two or more min eral grains which combine to fonn a . eutectic or the most fusible ratio in which the se n1inerals can cotnbine. The s pread of the g l assy cement from focus to focus in a clay of good vitrifying character i s s l ow and steady, and the proportion of grains whic h will not readily di sso lve is such that th ey readily form a sort of s keleton or frame work, h o ldin g the mass in its shape, while the g la ssy cement s l ow ly decomposes thetn and fills up the voids, cau s in g the well-known phenomenon called shrinkage . Practically all s ilicates when pas sing from the so lid state to a state of complete fu s ion, give off some gaseous matter. It may be the gas which the y have held in so lution and which is then occluded, or it may be from . r emnants of volatile matter not hithert o ex pelled, or it m ay be due to the swe llin g of gases caught in the int e rsti tial voids of the mass during the s hrinkage and unable to escape. Probably all three cau s es are responsible in most cases. This swe llin g agency i s at work as soon as the formation of g l assy cement be gins . If the process of fusion be carried a long steadi l y until a fluid bath i s obtained, the liquid will pass into a frothy stage in which the gas bubbles \vork their way to the top and escape, . but with continued heat and liquidity the bubbles finall y cease to form . It can thus be seen-tha t the clay product, in reaching its point of greates t density, does not r each the point where the gases are fully expelled but on l y the hi g he s t p oin t attainab l e zvithout causing the ir evolvement to seriously b egi n. This maximum den s ity is found at a point where the reduction in volume due to s hrinkage is equalized by the ex pansion due to gas es evolved. One force balances the other and for a time the volume of . the clay remains constant. This time may be long or shor t. In some clays of most excellent vitrifying habit, a heat treatment repre s ented by five or six cones tnay occur with sca rcely any change in size. In others the volume dim ini s he s rapidly and the minimum point begins at once to swell again, with no apprec iable interval. Such clay s cannot be burned profitably into hard products. There is no margin in which the burner can regulate hi s kiln, and a part of every kiln would 

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96 }'LORIDA GEOLOGICAL' SURVEY-I 5TH ANNUAL REPORT . . .. surely be overfired and bloated, part would be at its best density, and part 'Yould be underfired and not up to its best . . Such clays are sa. id to have a firing range. " . . . The fu sibility of days may be in several This is most frequently done by use of Seger cones, the thermoelectric pyrom eter, or an optical PY!ometer. The Seger cones cons ist of small slender pyr a mids of known com position (clayand fluxes) wh ic h at definite ten1peratures . They are arranged to repre s ent a series of fusion po i nts, each cone melting at. a few degrees higher than the next one below it in the series; In actual practice these cones are placed in a . protected place in the kiln they will not be in the direct flame and yet will . receive the av e rage heat from the fuel. They are placed in such a position that they can be watched through a peep-hole. If it is desired to reach a certain tempera ture in a kiln, a cone representitlg the temperature and two or three lower cones are placed in the kiln in a way they may . all be observed . . The lower cones melt af lower temper.atures and therefo r e ; the desired is being For example , . cones 3, and 5 may be used . When Nos. 1 and 3 are bent over in burning and No. 5 is still stan erect the temperature is between cones 3 and 5. The cone cannot be regarded as an exact measure of the degree . . of temperature. _It in reality measures pyrochemical effects instead and . . the . conditions of time and heat which will . accomplish certain results in fusion and vitrification. The cones usually melt quite close . to their fusion point, if heated slowly . These a wide application in the indust ii.es and are almost invariably u s ed by the manufacturers.of high-grade prod ucts. They are . used in several of the briek at;ld pottery plants in Throughout the United States the following cone are com monly used for the classes ' of ware indiCated :1 Common brick ............... ..... ........................... ... . . . . Hard burned, common brick . . . ........... .. ... . . . ...... , . ....... ... . Buff front brick ...... . .... . ...................... . . . . ...... .......... . Hollow block tile and fireproofing . . . . . . ............. , . ... ...•.......... ............... . . . ........ .. ....................... . . .... . lRies, H . , Clays, Their Occurrence, Properties and . Uses, p. 187 , 1908. 012-01 1-2 S-9 03-1 02-7 

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A PRELIMINARY REPORT ON CLAYS OF FLORIDA 97' Conduits .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-8 White earthenware . . . . . . . . . . . . . . . . . . . . . . • . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-9 Fire bricks ..••...... . . : . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . S-14 Porcelain . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-13 Red earthenware . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 010-05 Stoneware . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-8 Electric porcelain ............... ............. :............... . . . . . . . 10-12 For the composition and fusion temperatures of the Seger cone s eries see Appendix B. A . con1.parison of various ten1peratures u se d in the different kinds of products is shown in Fig. 1. The thermoelectric pyrometer is to a extent replacing the use "of the Seger cones in tneasuring temperatures. The greatest difficulty with its use is the cost of the apparatus. The type most widely used con sists of two wires, one of platinum and the other of an alloy of platinum and rhodium or platinutn and iridium, which are fused at one end while the free ends are connected with a galvanometer. One of the wires is encased in a small quartz tube to insulate it from the other. The two wires are then placed in a larger quartz or porcelain tube which is inserted into the kiln. The heating of the thermopile in the furnace generates an electric current which is conducted to the galvanometer which measures the intensity of current. The of temperature are measured by the an1ount of deflection of the needle. of the galvanometer. The galvanometer rriay be installed in the office some distance from the kiln and the temperature tnay thus be ob s erved at will. Some types of this instrument have an automatic recording device. The optical pyrometer is to some extent in measuring tempera tures. There are several forms on the h1arket. The principle of sotne of these is to compare the intensity of light in a furnace with that from some other source. In others the light emitted from the furnace is re fracted b y tneans of prisn1s a _ nd a c01nparison is n1ade with some standard. POROSITY The porosity of a clay is the volume of pore space existing between the clay particles and thus depends upon the s ize and shape of the particles making up the mass. Spherical grains would give a n1-aximum porosity, but cla ys of thi s type are probably unknown. In clays the grains • vary in size and are irregular in shape, which greatly reduces the poros_-ity. It has been shown, however, that increasing fineness n1eans increasing pore space. Porosity _ detern1ines the an1ount of water a clay will 

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98 FLORIDA GEOLOGICAL SURVEY-I 5'l'H ANNUAL REPOR'l' t:ll' IHPOHTANT nF?JNG f?AN8 7EHPERATVRES Or ClAY PROf)VCTS AND OTHER' roR CoMPARISON TE:NPRATUR CQ!M • TEl'fPE,('.lTlltff' AT WHICH JIAR/()(1$ 1/AR!ot/S THPRATUReS •c • r OF TIR CUY PROPVCTS 8 1/RNEP' rOR COMPARI.SON zooo S6s e --IPCO S462 Sl _,. -IS 1600 /'!Et.TIN& /1'0/NT Pc/R JCI.t0, A17o-/ /lf('l.TIN6 POINT AqOJ #StOr /4So•c{TIIt:OkUII. .P.('oP IN l'fLTIN6 POINT PU!i'II 1 Ht&HE$T TTMP IN STl!IL CONII'IKTF.Ii'i L()n'/JJT 1',('1(/JUHL HlT. PI or A l'lt'E aAI' MI!'J.TIN6 IVINT tlfC(71C C:V ,J:q. OJ • rr 80I L IN6 POINT OF Sn ANO P' ,.110•<: • C1 l'fLTING PO INT .INOHnUTI 15$6'"r: • 1600 2VJ2 #ELTING POINT CAST IHON 1510 •c" l'fELTINtS !"'INT SOI'TST.!'. /4'JrC • IZDO 2192 ltX>D Nln" . roo /292 U/2 . 4? liDO 572 ' ZIHJ HZ HIP 2/Z 41 /t:/(1 -1-NJ It -HI /.# , . I -01 Q / 0 IJ,-KYBJ116117 HEO FVU.I<'E 0 &ACK RrERNCES .r RIE$ -JJCTl/-1'/VOTt:.S CMNELL i/. I!JrL , A'/$ -C/.41"$ ./ONN WI/.LY /JT/iO 1906 * -/HOlt ANP STECL 184, , .!CHNA BEL H ,A IV tJ IJ()OK 01' Ml!iALlJ/lQV r TNVnTON-MATER/AU 01' • CAM.PDL't.t11.-fll (lf? ACTVA'C 0/1' IRO/'IAN/J.fiCFL " &IJTIII -tiS ttl 4Vt.UTIN NIJ, -I.tt:l ll1f AH'/C,l/1 PI' dtle'N('L' 'JP()6 11130 Frn. 1. IV• 1400 •c • , 0/?THOC/..AS NLTS 1300•<. ('.S t11•T' • eN.SVOO"f:) .. MELTING POINT A/.8/T& , . NLTIN6 pOINT Cot INS•(?. NELTIN6 POINT,.., to4o•c 111 I'IELTIN6 POINT A!l 1000-r:11 80ILJN6 POJNr Zit 9So-c• ;ffE'LTIN6 Pt)tJVT AI rPO OW:"' HEL.TIN<$ POINT Zn "' Boii.IN6 PC/NT Hg Sdo•C II MELTING POINT PI> SStJ•c• MELTI:. s PO INT S'l I U-t: • OROINARJ' TEMPE'IlATLIR eo•<. rRFFZIN6 POif.IT WATCii' o•c l"llFE'.riN6 A::JtAJT IIJ • 

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A PRELIMINARY REPORT ON CLAY S OF F!..ORIDA 99 absorb and in this way influences "the amount of air-shrinkage. Porosity also influences the rate at which the ware can be dried . The larger the . pore space the more rapidl y water can e sca pe . Also in the burning proce ss a clay porous until the point of vitrification is reached. A low poro s it y in burned products is u s ually de s ired. TRANSVERSE STRENGTH The transverse strength is the resistance which an air-dried cla-y offer s to rupture or breakage. It is usually expressed as modulus of rupture in pounds per square inch. It was formerly the custom to determine the tensile strength of a clay in much the same way that cements are tested . It has been shown. however, that the tensile strength sta nd s in direct relation to the transverse strength .1 The tran sverse strength test is in reality a closer approximation of the conditions to which the ware is su bjected before burning, and for that reason is the tes t commonly applied in modern clay investigation. The transverse strength is an index of the ability of the clay to withstand the shocks and strains of handling incident to it s molding, drying, and preparation for firing. A clay of high strength will suffer less loss from breakage in the manufacturing proce ss than a clay of low strength. BONDING STRENGTH The bonding power of a clay is it s ability to withstand the addition of non:-plastic material. A clay whicq will allow the addition of a large amount of sand, for example, without s eriou s ly affecting it s stre n gth is sa id to have a high bonding power. The bonding power of a clay is of practical importance becau se in the manufacture of high-grade wares as electric porcelain, chinaware, etc., non-plastic ground flint and feldspar are often added. lRics & All en, "frnns. Am. Ceramic Soc., Vol. XII, p . 141, 1910. Bleininger and Loomis, Trans. Am. Ceramic Soc., Vol. _XIX, p. 601, 1917. 

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100 FLORIDA GEOLOGICAL SURVEY-I5'l'H ANNUAL REPORT . CHAPTER V TESTS MADE UPON CLAYS The methods of testing cla ys are now fairly standardized and are somewhat unifortnly followed with the . result that clay technolqgists and investigator s hav e a reliable ba s is upon which to / cotnpare the prop erties of various clays. The measurement of the plasticity of a clay still remains a matter of personal opinion, for no satisfactory n1eans of measuring it has as yet been devised. T . he terms employed to describe the plasticity of a clay are onl y relative and will of course vary to some extent the indi vidual. Plasticity is usually described as "good", "excellent", "poor", "low", etc. A clay having good or excellent plasticity is said to be "fat", and one having low or poor pla stic it y is de s cribed as being " lean. " The water of plasticity is a more definite factor and can thus be accurately measured. The water of plasticity i s the amount of water necessary to give a cla y its maximum plasticity. It is expres s ed in terms of percentage based upon the dry weight of the cla y and is by weighing a test piece at maxin111n1 pla s ticit y and agai n weighing it after all the moisture has been driven out b y first drying at r oo tn ten1perature and finally at 110 C .. until it has a weight. The water of plasticity te s t indicates the amount of water necessary to' bring a cla y to its point of maxin1un1 plasticit y in which state it can be worked. The shrinkage water is that portion of the water of. plasticity which escapes up to the point where air-shrinkage ceases, or in other words, it is the water lost in air-dry ing. The clay without the sh rinkage \;\,'ater is at the point of maximum air-shrinkage in which condition the clay particles are in con tact. The pore water is that portion of the water of plasticity which remains in the inter-particle spaces after the point of maximum airshrinkage has been reached. It can be driven off only by hea.ting the test pieces to 110 C. The pore wate r plus the shrinkage water is the water of plasticity. . The staking of clays is the property possessed b y thetn when dry , of crumbling into a flaky or pulverulent mass when imn1er se d in water. In order to determine this property it is necessary to first dry the test pieces at room temperature: Then all the ren1aining nioistu re is driven off by heating them for two hours or longer at 110 C. They are then 

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A PRELIMINARY REPORT ON CLAYS OF FLORIDA 101 placed on a screen having four meshes to the and carefully immersed in water. The time required for the clay to disintegrate and fall through the screen is noted. The plasticity of certain clays is increased by weathering which thus fadlitates tempering. The slaking test indicates the weathering quality of a raw cla y .and may be employed to ascertain whether or not weathering would facilita t e handling. Also a clay which slakes r eadily is more eas ily washed than one requiring a long time for s laking.\ In the case o f high-grade clays a mixture of 50 'per cent clay and 50 per cent potte r's flint is .made into test piec e s and slaked. This is one indication of the bonding strength of the clay. ( \ . In the determination of volum, e air-shrinkag.e volume of the tes t piece is detern1ined in cubic centimeters. Then j t is allowed to dry at room temperature followed b y period of drying at 110 C. until constant in weight. The volume in cubic centimeters is again determined and the lo ss in volutne is calculated in percentage terms of the dry volun1e. The linear air sh?-iuka , ge is computed by dete.rmining the reduction during drying in the length of a line of known length marked upon the t es t piece when freshly tnolded. This shrinkage is expressed in percentage terms of the original lengt h. The volwme fi1'e sh?-inkage is detern1ined after firing at the respective ten1peratu r es . The reduction in volume after the completion of the air shrinkage i s determined in cubic centimeters and calculated in percentage terms of the o riginal dry volume. The lin ear fire after firing at the various temperatuFes in tJJ.t tht.li,nea;. air shrinkage. It is ex• • • • • • • • • • • • pressed 1n t erms based upon of the mark. Botl} t1\e.'1ii1e 'ar air and fire shrinkage may a\'9he calculated from the . • :Toltme and shrinkage are simply different! rneth6cfs' ol the property of a • • clay. The shrinkage of a cla y both in drying and in firing is obviously an in1portant factor. The absorption test i s made to determine the amount of water a clay will absorb. The weight of the test pieces after each firing is de tern1ined, after whi ch they are imme r sed water at roon1 temperature for twentyfour hour s and v ve i g hed again. The absorption is the amount 

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102 FLORIDA GEOLOGICAL SURVEY-15TH ANNUAL REPORT of wate r absorbed expressed in percentage terms of the dry weight of the fired test piece and i s obtained by the following formula : Absorbed weight-dry weight ---------XlOO==% absorption . dry weight A knowledge of the amount of wa t e r possible for a clay to abso rb i s very des irable as thi s property may s eriou s ly affect it s u s efulness. A small percentage of absorption indicate s that the wa re will absorb a correspondingly sn1all a mount of moisture. This in t u rn indicates a better resi s tance to f rost action, l ess l ikelihood of the appea r ance o f so l u ble sa lt r and i ndicates the general hardne ss of the ware as well a s the general progress of vitrification. . ' The porosity of a clay i s an expression of the pore s pace it contain s. The poro s it y i s d et ermined after b y boiling the test piece in water f o r one h our after it it has absorbed as much water as it will. This causes the p i ece to becon1e saturated. Its weight suspended i n water i s also obtained. The p o ro s ity i s express ed in percentage terms of the original weight of the test _ piece and obtained by the following formula : Saturated weight-dry weight -------------XlOO==% porosity. Saturated weightsuspended weight . By u s e of the porosity determination the progress of v itrifi catio n is .Know n. The point of minimum por os i ty, or maximum density, is the point of complete vitrification. If plotted on cro ss-sec tion paper whe re percentage of porosity and at:e the factors , the resulting curve drops more or le ss :ul)til it a.pgr0ac he s the temperature of vitrification, risin g .. , as the tempera ture v is reached. When the porosity. inC'rtases the clay is said to be overfir.t!d : The porosity c of a day prod ur.t an in its dttr . ability and c (l (' ( ( non-condu ctivity to heat. , " , , J • , _ , , . : Porosity and absorption stand in direct relation to each otner . The curve s, when plo t ted, are es s entially parallel. The d et ermination of absorption is essential in structural materials and porosity in fireproofing ware. The transverse strength or tens ile strength indicate s the ability of a clay to . withstand the shocks and strai ns handling. The transverse 

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A PRELIMINARY REPORT ON CLAYS OF FLORIDA 103 strength and tensile strength stand in direct relation to each other. The tensile strength is determined by molding the clay into briquettes similar to those in testing cement. These, after being properly dried, are pulled apart in a tensile strength machine. The cross section of the tensile strength in pounds per square inch is The tensile strength test is now superceded by the transverse strength test. In determining the transverse strength, bars .of clay six inches long and one in<;h in cross-section are made. They are then dried first at room temperature and finally at 110 C. After the width and thickness of the bars lre n1easured they are placed on s upports six inches apart and pressure is applied to the upper surface n1idway between the supports . The modulus of rupture is then computed in pounds per square inch by the following formula : 3 w 1 Modulus of Rupture ........... --2 b h2 Where w is the breaking load, 1 the distance between supports, b the breadth of the bars, and h the height of the bars. The bonding test is made in order to the b<;>nding power of a clay. This is made by mixing equal part s of standard sand and clay and the mixture is molded into bars and broken as in the transverse strength test. The modulus of rupture is then calculated. The bonding power of a . clay is its ability to carry quantities of non-plastic n1aterial. The n19dulus of rup ture of the s and-clay tni xture n1ay be e i ther higher or lower than that of the clay alone. The color of a fired clay is always of importance and hence is noted . ., ) This is of the raw clay is no indica• • • • ' ;a ) ) J 0 ' ' ) ,) tion of its fire.d 'Q.lo.t:• ' • • . ' .: , .) • . ... .. .)) . •,•,• •,• • • • • • ) ) 0 • - • • • • ? ) , • •• '• >.,>),) .. ' 4 , , • 1) , ... , ) , 0 ) • ) 0 0 0 , • , • ) ., , ) ' 0 .) ) ., ., ., ., ) .) ? ,,),,, ) J)l. l ) ) ) ) )) )l , , ) :) "' ) , , ., \) ,, , . .. ., . ) ., ' 1, o "''"'._"..,"'v n , .. , > > 

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104 FLORIDA GEOLOGICAL SURVEY-15TH ANNUAL REPORT CHAPTER VI KINDS. OF CLAYS AND THEIR. US'ES This discussion of the kinds and uses of cla ys is based upon the con1mercial cla ss ification and i s in no way related to their geological occur rence or origin. The . u s e of any one clay, moreover, is not a l ways re stricted the general t yp e of mentioned here , but tnay be employed for other as well. For example, a stoneware clay may be u s ed for roofing tile or terra-cotta, but its chief value lies in the fact it i s adapted for the manufacture of stoneware. KINDS OF CLAY Kaolin-This term was formerly used to include oril y a refractory white-burning re s idual cla y compo s ed n1ostly of s ilica, alumina, and chemically combined water with a low per c enta g e of fluxing properties, but now include some sedimentary clays of s i milar phy s ical properties. l(aolins have a low airs hrinkage, lo w modulus of rupture, low bonding power, and tl\eir plasticity is cotnmon l y poor. They are used chiefly in the manufacture of high-grade white wares: Ball-Clay-A ball clay is a plastic white or nearly white-burning sedimentary clay of high refractoriness and bonding power. The air and fire-shrinkage i s frequently high. Ball-clays are used chiefly in the manufacture of white ware to increa s e the plasticity, bondin g s t rength and density after firing. . Fire-Clay-A fire-clay is h igh l y refractory, fusing above cone 27, of variable plasticit y, shrinkage, transverse strength, and color and has a l ow percentage of iron , c:Ukali-es, Hme" magnesia, and titaniutn. t) ( ( C ( C. C. 0 I C' 0 Stonewa r e-Cla'j i-A • i s ':Of :g9'q'd; .. plqsticity, medium to high trans verse toughness, den s e at a comparativel y lo\v (cones 6-8). Its color i s .. fatl:ier!}11portant r r " c ' C'l " but is .gpl"y, cream ' • " ( fr: be of stnooth, even and shou1d •nave' a and goqd ' yitri ying qualities. Most modern stoneware, however, is made from a hlet1d or mixture of severa l clays. Stoneware clays are also often used in the manufacture of other types of products, as art ware, earthenware, roC?f ing tile, and terra-cotta. ott a Cla'jls-Ciays for this purpo s e shou ld be semi-refrac tory, of fair plasticity, high transvers e strength, high b .onding power. 

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A PRELIMINARY REPORT ON CLAYS OF FLORIDA 105 They should be dense-burning, have a low shrinkage, and be free from The ab s ence of soluble salts is an essential property. Most terra cotta is made from a blend of several clays and is commonly fired at about cone 6 or 8. Gray or buff-burning fire clays are comn1only used, but in most cases. an artificial color is applied to the surface of the ware. I Sewe1-pipe Clays-Clay for sewer-pipes should have a low shrinkage; high and be free from warping and cracking. It should be vitrified, hence a cla y h ' igh j . n is best. but at the san1e tin1e it should have a long firing range: Vitrification should be reached at cone 3 or 4, son1e clays used vitrify at a low .er temperature. This type of ware is commonly covered with a salt glaze. Clays suited for sewer pipe manufacture are similar to those used for paving brick. A darkcolored sewer pipe is most cdmmonly called for on the market. Brick Clays-Clay for common brick is usually impure, often sandy, high in fluxes, of medium plasticity , variable strength, . color and porosi ty'. They are in n1ost cases red-burning but sometitnes gray, cream, buff, or yellow. Common . brick-clays are widely distributed . . . Face brick, or sornetin : es called front or pressed brick, requires a better grade of clay than cotntnon brick. They n1ust have a unifonnity of color in burning, freedom from warping or splitting, absence of solu ble salts, good hardne ss after firing and low porosity. The shrinkage and transverse strength are variable. Front brick n1ay be red, white, cream or buff after firing. Such clays are con11nonly fired frotn cone 1 to 9. Clay for face brick should be n1_ ore plastic than that for con1n1on brick so that the ware n1ay retain its fonn better and pre s ent smooth faces and square corners. Piasticity, however, is not an itnportant factor in dry-press n1ethods. The clay should have a good _ firing range and should be burned so hard that it cannot be scratched with a knife. Clay for paving brick should have the same general properties re quired of a sewer-pipe clay. Ordinarily clay is burned to the point of vitrification but from son1e clays the toughest product is obtained before is reached. Such clays should have fair plasticity and good transverse strength. The firing range should be at least 150 C. Hollow block, fire proofing, and drain tile all require clay of the same characteristics; in fact, they may all be made from the same kind of clay. The of clay suitable for these products is quite variable. They should a fair transverse strength, burn to a hard but n0t vitrified body at a comparatively low cone ( 03-1), and should have suJfiCient plasticity to flow stnoothly through the peculiar shape of die necess _ary to form them. 

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106 FLORIDA GEOLOGICAL SURVEY-15TH ANNUAL REPORT Slip-Clays-A slip-clay is one used as a natural glaze. It should be of fine, even texture, have a high percentage of fluxing impurities, and s hould rnelt to a greenish or brown glass at a low cone. Miscellaneous-Clays u s ed when burned, not include . d in t .he above mentioned groups, are: Gumbo-clay, having a high shrinkage, dense character, and fine g rain, is used extensively as railroad ballast. Saggerclay i s used in making the saggers or box es in which ware and other high g rad es of pottery are b.urned to protect them from the flan1e and fuel gases. Their refractorine ss must be above that of the product burned. \ i\Tad-clay is a low grade of fire clay u se d for sealing the joints between saggers when the y are se t in the kilns . Portland cement cla y is that u s ed in the artificial mixture of s ilica , alumina and lime w hich com po s e s Portland cement. Clay or s hale usually supp lie s the silica and alumina and limestone or marl the lime. The adaptibility o f a clay for Portland cen1ent can only be determined from a chemical analysis . Many clays are used in the unburned condition as paper fillers; paint pigments, abrasives, etc . USES OF CLAY The uses of clay are many and varied and any attempt to list all of them would be hopele ss. The following uses li sted by Ries1 s ummarize s tho s e of raw clay as well as those of the fire or burned clay: Domestic-Porcelain, white ware, yellow ware, Rockingham ware for cooking and for table service, majolica stoves, polishing brick, bath brick, firekindlers. Structural-Brick, common, front, pressed, ornamental , ho ll ow, glazed, adobe, terra-cotta, roofing tile, glazed and encaustic tile, drain tile, paving brick, chimney flues, chimney pots, door knobs, fireproofing, terra-cotta lumber, copings, fence posts . Refractories-Crucibles and other assaying apparatus, gas retorts, fire-brick, glass pots, blocks for tank furnaces, saggers, stove and furnace bricks, blocks for fire boxes, tuyeres, cupola molds, mold linings for steel castings. Engineering-Puddle, Portland cement, railroad ballast1 ' water conduits, turbine wheel s, e lectrical conduits, road metal. Hygienic-Urinals, closet bowls, sinks, washtubs, bathtubs, pitchers, sewer pipe, ventilating flues, 'foundation blocks, vitrified bricks. Decorative-Ornamental pottery, terra-cotta, majolica, garden stands, tombstones. Minor Uses-Food adulterant, paint fillers, paper filling, electric insulators, pumps, fulling cloth, scouring soap, packing for horses' feet, chemical apparatus, condensing worms, ink bottles, ultramarine manufacture, emery wheels, playing marbles, battery cups, pins, stilts, and spurs for potters' use, shuttle eyes and thread guides, smoking pipes, umbrella stands, pedestals, filter tubes, caster wheel s, pump wheels, electric porcelain, food rules, plaster, alum. 1Rie9, H . , Clays, Their Occurrence, Properties and Uses, p. 252, .1908 . To this li s t of clay products should be added tuipentine cups, w hich are very exte n sively used in Florida. R . M. H. 

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A PRELIMINARY REPORT ON CLAYS OF FLORIDA 107 CIIAPTER VII GEOLOGY OF THE CLAYS OF FLORIDA STRATIGRAPHY The formation s exposed at the surface in Florida are all of the younger periods, ranging fron1 . Eocene to Recent, . as may be seen from the accompanying table. Each period of the territory is represented and each contains clay to a greater or l e ss extent. TABLE OF GEOLOGIC IN FLORIDA ERA PERIOD FORMATION THICKLITHOLOGIC RE-NESS DESCRIPTION MARKS -Recent Recen t ? Sands and Clays Pal m Beach Lim estone ? Marine Limestone tMiami Oolitic Limestone ? Marine Limestone I C:"' II) CIS ....... 0 c: Key Largo Limes tone ? Marine Limestone cu cu. -... Pleistoce ne b"V E II) Key West Limestone ... ? Marine Limestone Ill ...... CIS ... :J Lostmans River Limestone ? Marine Limestone u u CJ cu..C:-o Fort Thompson Beds ? Freshwater and X 0. Q e :J Marine Beds -Lafayette Formation ? Sands, Gravel s Ill and C l avs :J 0 Citronelle Formation ? Sands, Gravel s j II) c: and Clays CIS ... 0 Pli ocene Bone Valley Formation ?-100' Pebble Phosphate, 0. 8 Gravel, Clay, II) ... Sand fi Alachua Clay Formation 100+ Non-Marine C l ays Caloosahatcbee Formation 0-1 00 ' Marine Marls Nashua Marl Formation 01 00' Marine Marls CIS ..... Charlton Marl Formation ? Mari ne Marls .... . ... II) C hoctawhatch ee Formation 20'-50' C hiefly Marls } Con-f-. tern-Jacksonville Formation ? Limestone, Clay pora-Miocene Alum Bluff Formation 10 0' -200 ' Sand, Gravel, neous Clay, Limestone, . Fuller's Earth Tampa Formation ? Limestone, Clay } O l igocene Chattahoochee Formation 100 ' -200 ' Impure L i mestone, tem -C lay pora-neous Marianna Formation 30+ Limestone Eocene Ocala Formation 20' -50' Limestone EOCE-NE The Eocene is repre sented by the Ocala formation which is expo s ed chiefly on the \ve s tern side of peninsular Florida fron1 Pasco to Lafayette cou n ties and also in the northwestern portion of the State in Jackson \ 

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108 FLORIDA GEOLOGICAL SURVEY-15TH-ANNUAL REPORT and Holmes counties . It consists chiefly of a soft, white, granular lime stone which is locally silicified. Its thickness rarely exceeds fifty feet. A thick mantle of surface sands overlies large of this formation on its westward margin. OLIGOCENE The Oligocene is represented by three formations: the Marianna, the Chattahoocpee, and the ' T4e Mar ia nn a formation is a soft, light-colored, granular limestone occurring only in a stnall area in the northwestern part of the State in the vicinity of Marianna and Cottondale in Jackson County. The for mation as it occurs in this area is rather thin, slightly over thirty feet, but its upper portion has probably been removed by erosion. The Chattahooch e e forntation is a soft, itnpure argillaceous or claye y limestone extending through portions of Suwannee, Han1ilton , Madison and Jefferson counties south of the GeorgiaFlorida boundary and alsq farther westward in Gadsden, Jackson and Holmes counties. In the re gion west of the Apalachicola River the Chattahoochee limestone is over lain by a mantle of in1pure, sandy clay of variable thickness and reddish or yellowish irt color. This in turn grades, at times sharply, into a gray jointed clay below. Thes e clays . are probably residual from the Chatta hoochee limestone. The thickness of the Chattahoochee formation ranges from 100 to 200 feet. The fonnation is a hard silicious limestone occurring at the head of Tampa Bay and extending northwestward through Hills borough, Pasco and counties. It is probably . to. some extent contemporaneous with the Chattahoochee formation. MIOCENE The Miocene peri?d in Flo_rida is represented by the Alum Bluff formation, .the Jacksonville formation and the Choctawhatchee forma:.. tion. The Alum Bluff formation consists of sands, clays, sandy lime stones, . etc., depos_ited unde ' r both terrestrial and marine conditions. It contains much phosphatic and perhaps all of the fuller's earth deposits of the State: It extends from the northern side of the Ever glades and the Manatee River northward through the central portion of t!1e to the Ge orgia-Florida boundary, the . nce west-

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A PRELIMINARY REPORT ON CLAYS OF FLORIDA 109 ward, in a somewhat broken succession in Florida, to almost the ex tren1e west encl of the State. It is probably the most widespread forma tion exposed in ti-le State. The Jacksonville forn1ation is a term applied to deposits known in the vicinity of Jacksonville and having a limited extent. Its fauna indi cates a later age, but otherwise it closely resembles the Alum Bluff formation. The Choctawhatchee formation consists of marls, sands, and clays exposed in portions of west Florida. PLIOCENE. To the Pliocene are assigned several formations consisting essen tially marls, sand and clays representing marine and fresh-water conditions of sedimentation. Several of these are probably contetnporaneous. PLEISTOCENE The Pleistocene deposits, which here includes those of Recent age, as well, are of widespread distribution and variable lithologic character, representing both terrestrial and marine conditions. They are found principally in the southern extremity of the State and along both the Atlantic and Gulf coasts. Numerous deposits of this age, while rela tively thin, are widely distributed over the i . nterio . r of the State. GEOLOGIC AGE, OCCURRENCE AND DISTRIBUTION OF THE CLAYS There is not space within the limitations of this r.eport to treat exhaustively the geologic age of the clays of Florida. In reconnaissance work it is often difficult and at times itnpossible to ascertain the horizon to which a clay deposit should be a s signed, owing to its frequently limited areal extent, lack of fossils and imperfect exposures. The geologic map issued with the Fourteenth Annual Report of this Survey ( 1922) has been largely conformed to in . assigning clays to forn1ations already es tablished and sotnewhat widely distributed within the State. It is to be noted, however, that within an extended area of exposure of one forma tion there may be numerous deposits of a tnore recent age. This is particu larly true ii1 Florida where the great number of sink-holes, swamps, and small strean1s of low gradient have afforded conditions favorable for the of clay deposits. Selfards1 has pointed out that the sinks pos!Sellards, E. H., The Relation of the Dunnellon Formation to the Alachua Clay, Sixth Annual Report, Florida Geol. Survey, p. 162, 1914. 

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110 FLORIDA GEOLOGICAL SURVEY-15TH ANNUAL REPORT sibly began to:form in Florida during the late JV!iocene and continued actively through the Pliocene and Pl_ eistocene to the . and that during the Pliocene the sink-holes, ponds, lakes and surface streams reached their abundant and typical development in Florida. Many of the sink-holes form lakes which receive sediments carried in from the areas. This sediment settles to the bottom; forming layers of clay, sand or an intimate gradation between the two with varying amounts of other materials, depending t:tpon the character of the sedi.ment carried in and the character of the currents within the lake. Clays formed in the flood-plain of streams or filling the channels of former streams are also of frequent occurrence in Floriqa . . Deposits of these types may occupy an area underlain by one formation and except on a very detailed or large scale geologic map no differentiation between the two horizons will be made. yYhere the determining features of such de posits are evident the clay is termed lacustrine .or a flood-plain clay; etc., as the case may be. There is moreover in Florida a vast mantle or coating of surface sand and sandy clays of variable thickness which probably is of residual character resulting from the alteration of surface materials. This mantle often masks the true character and extent of the underlying form-ations. Indeed, in son1e s.ections of the State, particu larly in west Florida, literally hundreds of square miles appear to be covered with this material where it caps the hills as well as the lower areas. The clay content of this covering material is often quite high, at times giving it t!-l. e appearance of a plastic joint clay. It is, however, un suited for the manufacture of clay pro<;lucts. The Ocala formation which, in Florida, is the sole representative of the Eocene Period, consists primarily of limestone. The limestone in places . has been altered to flint and in other places has weathered into a residual clay. These residual clay deposits, as is characteristic . of limestone residuals, are of variable depth and limited lateral extent. This formation occupies an extensive area on the Gulf side of the northern part of the peninsula extending throtigh portions of Pasco, Hernando, Sumter, Citrus, Marion, Levy, Alachua, Cglumbia, Lafayette, and Suwannee counties. There are within this area numerous srnall outlier s of younger surrounding deposits and also local areas of ;Pliocene to Recent lacustrine or fluviatile sediments. The Ocala limestone also 

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A PRELIMINARY REPORT ON CLAYS OF FLORIDA 111 outcrops in Jackson and Hohnes counties where again it forms local residual clay deposits. T-hese residual clays are variable in their physical properties. They range in color from a gray or greenish-gray to a brown, ta!l or light buff. Son1etimes this range of color will be found in a single deposit with the lighter colors at the bott-om. They are usually fairly plastic though at times somewhat stiff at the surface, becoming more plastic with depth. In places they are quite sandy and at titnes contain flint and limestone fragnients or calcareous or ferruginous con cretions. Red or dark l;>rown-burning clays are the rule, though buff aries are found. Most of these clays have a high airand fire-shrinkage also crack and warp badly in drying and burning. The resulting losses are The deposits range in depth from a few inches to as much as twenty feet, . with a slight overburden, and in lateral extent often cover as much as sixty or eighty acres or more. Sotne of the s e clays found in eastern Levy and western Marion and Alachua counties are suitable for common brick. None of the Ocala clays are now being utilized. The Marianna formation (Oligocene) is a thin limestone of limited extent in Jackson Co _ unty. Some very small and local residual clay occur in this area. They will not be treated here, however , on account of their in sufficient size p.nd their calcareous character. The Chattahoochee fonnation, also of Oligocene age, occupies an area in the vicinity of the Suwannee and Aucilla rivers, a sn1all area on the Ochlocknee River, and a belt in west Florida extending westward from the Apalachic _ ola River to beyond the River. I . t consists essentially of a very impure, soft argillaceous limestone with some clays and marls. Residual clays result from the ering of this formation and hence are frequently found in the areas where it is exposed. The clays interbedded with the limestone are usually calcareous, greenish to gray in color, break with a slight con choidal fracture, are fairly plastic, but at times stiff and often very ' sticky. The residual clay resulting from the decomposition of the Chattahoochee is a plastic joint clay containing some calcareous concretions and geodes. Numerous deposits of it are located in Suwannee and Hamilton counties, in western Gadsden County, and in Jackson and. Hotmes counties. None of the Chattahoochee clay is now being utilized, although brick plants have formerly been operated near 

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112 !"LORIDA GEOLOGICAL SURVEY-I 5TH ANNUAL REPORT Au cilia in Jefferson County and at River Junction ip Gadsden County. Some of the Chattahoochee residual clays may be looked on with favor for the manufacture of common brick. The Tampa formation is likewise of Oligocene age and is . consid ered to ' be contemperaneous with the Chattahoochee formation. It con sists of a hard silicious limestone exposed at the head of Tampa Bay, westward to the Gulf, and northeastward through Pinelia?, Hills borough, Pasco and Hernando counties, with some outliers extending farther northward. The limestone is locally weathered to residual clay. Sedimentary clay is also widely distributed in this formation. Some of these clays, both sedimentary and residual, are suitable for common hrick. . A brick plant now being operated at Brooksville is using a residual Tampa formation clay. The upper two feet of the deposit is dark brown and somewhat sandy. The lower n1ember averages about eight feet in thickness and is of a very light colot. The clay grades _into a limestone at fne bottom of the and contains numerous flint concretions and fragments in the lower portion. The contact between the upper dark clay and the lower white clay is well defined and probably represents a former water table. Several abandoned brick plants have in the past used the Tampa clay. One of these, the G>ld Tampa Brick Co., worked an exposure on the Hillsborough River about five miles northeast of Tampa. This deposit had the following section : . White sand and soil <Pleistocene) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 feet Unconformity' ............................................... . Light green plastic clay (Tampa) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 feet The clay contained n umerous _ cherty concretions. This same clay is exposed in several places along the Hillsborough Riyer, near Oldsmar on Tampa Bay, and at several points, on the Gulf coast in the of Tarpon • Springs. . The Tampa form ation has a sedir:nentary light green plastic clay above the chief limestone horizon and another clay strata of similar char-; acter below the limestone. This lower clay was found to range from forty-one to sixty-four feet in thickness in wells drilled at the Tampa Water Works. The upper clay horizon is the one mdst frequently ex posed and is the one formerly used in the manufacture of brick. 

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A PRELIMINARY REPORT ON CLAYS OF FLORIDA 113 . . The Alum Bluff formation of Miocene age .is probably the most widely dis . tributed of any of the forn1ations exposed in Florida: extending in a belt of variable width from northern Oka1oosa County eastward to the northern part of the peninsula, thence southward to the lVIanatee River and the northern of the Everglades. It consists chiefly of interbedded sands, gravels, n1arls and clays, including the fuller's earth, each of variable and extent. These sedin1ents are often <;ross-bedded indicating conflicting currents. They repre?ent terrestrial, fresh-water and marine shallow-water con..ditions .of sedimentation. The clays are usually thin, sandy, and variable in lateral extent. The Alum Bluff formation doubtle s s represents conditions of s e d in1entation not very different . frorn those in operation in Florida at the present tin1e.' The fuller's earth deposits are confined to a lin1ited area in Gadsden and Leon a smaller area in Manatee County, and isolated deposits in Marion and Alachua counties . overlying much of the fuller's earth in Gadsden County are two strata of clay: A section in one of the Fl<?ridin ' Cotnpany's mines near Quincy shows the following: Soil and surface sand . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 feet . Unconformity .......... , ...................... : ............. . Clay, green, plastic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 feet Apparent unconformity ........ : ........................ : .... . Clay, greenish, sandy ........ ; ................. :. . . . . . . . . . . . . . 8 feet Fuller's earth ................................... ............ . An on the about one tnile east of Quincy, how ever, ex hibits only one stratt1n1 of This is greenish in color and plastic. In other localities the clays above the fuller's earth absent In the vicinity of Quincy this clay has forn1erly been used for the manu facture of cotnmon brick and is very suitable for that purpose. . In the vicinity of White Springs the Alum Bluff clays are promi nent. At the bridge across Suwannee River the following section was observed : Sand and soil (Pleistocene) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 feet Unconformity ............................................... : Green, plastic, jointed clay .. , . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . 8 feet Sand and marls .................... . . . . . . . . . . . . . . . . . . . . . . . . . ? An exposure on the 'White Springs-Lake City highway, about two n1iles northwest of Lake City, exhibited the following sections: 

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114 FLORIDA GEOLOGICAL SURVEY-15TH ANNUAL REPORT Sandy soil ............ . . . ........ ... ..... . ....... ........... . Brown and gray sand with clay .................. . . . . . ........ . Gray clay ........ . ........................... . . . . ........... . White and green sandy clay .. ........... .......... . . ..... . . . . . Green plastic clay .................. ....... .... ........ ... ... . . (Bottom of clay not exposed.) . 2 feet 3 feet 3 inches 3 feet . 6 plus A jointed has been used in the manufacture of common brick . in two localitie s in the vicinity of Lake City . At Campville, in Alachua County, a clay which is of Alum Blu:ff age is now being used for a good grade of common A section of this deposit is : Soil and sand . . . ................................. ... ....... . White sandy CI ay . . ..... .............. . . . . . . . . ..... . ....... .". Red and gray spotted clay ................... . . . . . .... ....... . . Red sandy. clay ......... ............ . . ............ . . .' ....... . 3 feet 7 feet 16 feet ? Green and grayish Alum Bluff clays are exposed in Hatchett Creek one mile northeast of Fairbanks. Phosphatic clays, greenish to gray, are also found near Riverview . in Hillsbora.ugh County and along the Gulf coast north of Dunedin in .Pinellas County. This latter area prob ably represents an isolated remnant of the Alum Bluff. There is throughout much of Alum Bluff region a superficial deposit of red sand and clay . This material consists of coarse quartz, sand, at gravel; a variable clay content which is often high . Small flakes of mica are also often present in large quantities. This material is extensively used for road metal in Lake, Polk, Orange and Marion counties in t)le peninsula and also in Leon, Gadsden several other cqunties in west Florida . TtJ.ese deposits are only tentatively in clu4ed in the Alum Bluff. It is exceedingly doubtful if this material is Miocene . Some of it is probably a residual mantle resulting from the weathering of Bluff formations as well as other sediments. While much of it may have originally been Bluff deposits it has been largely reworked by subsequent streams and currents . Its age may be regarded as still unsettled. It is doubtful if any clays representing the Jacksonville formation are expo s ed. The clays of Black Creek below Middleburg and those underlying South Jacksonville may be of Jacks onville age, but it seems more l i kely that they are of recent . deposition. . The Choctawhatchee formation, Miocene , underlies a limited area in west extending through Leon, Liberty, Calhoun, Washing-

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A PRELIMINARY REPORT ON CLAYS OF . 115 ton and Walton counties. It consists of a marl member which is over lain by a grayish clay . The clay ranges in thickness from about ten to approximately thirty feet. This clay is the southeastward extension of tl1e Pascagoula clay which is exposed through portions of the Gulf states to Eastern Texas. The Charlton formation is a marine Pliocene marl extending along the northwe s t side of " Nassau County next to the St. 1tfarys River. lt is _ not known to be associated with clays. The Nashua formation, also Pliocene, consists of interbedded marls and clays and occupies a small . area in Flagler. and Putnam counties. The clays are usually of limited extent and frequently thin Some of these are and all are to some extent sandy. Many , howev . er, may be used for structural materials. Several of these clays formerly been used in the manufacture of common brick. The Caloosahatchee formation, likewise a marine marl, und e rlies .a small on the Pinellas . peninsula qn the west side of Tall?pa Bay, and a much larger area in the 'region of the Caloosahatchee River. ' A few calcareous clays accompany the n1arl. The Bone Valley foro1ation, Pliocene, occupies a limited area east of Tatnpa in Polk, Hillsborough, Manatee and Hardee counties. It is a fluviatile deposit chiefly noted for its pebble phosphate content . and is extensively worked for phosphate in this region. It also contains a clay known throughout this region as the Bartow clay . . . This tern1 was formerly applied to the n1atrix carrying the pebble phosphate, but now the application of the term is limited to the sa nd y clay overlyingthephos phate horizon. The Bartow clay is widely distributed in this region and is used to some extent as a road-surfacing metal. Its high santl content greatly reduces its plasticity, making molding and difficult. When burne :l, however, it is suitable for common brick. . The Alachua clay is a terrestrial Pliocene forn1ation composing sm all disconnected areas in central Florida . This was forn1erly u sed to designate of a blue to gray sandy clay which . had ac cumulated in s ink s apd ponds during Pliocene times and encased numer ops vertebrate ren1ains. It is now understood to include also the hard rock phosphates fonnerly known as the Dunnellon fonnation . The Alachua clay forn1ation contains n1any local clay deposits in Alachua, Levy a nd counties. The .Citronelle fonnation, a Pliocene deposit exten'ding through the Gulf states has only a lin1ited extent in Florida. It extends through 

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116 FLORIDA GEOLOGICAL SURVEY-I 5TH ANNUAL REPORT portions of Escambia and Santa Rosa counties in western extremity of the State. It is in most places overlain by Pleistocene deposits. An exposure which may be regarded as typical of the Floridian areas is seen at Dexland Bluff on the Escatnbia River east of Gonzales (see Fig. 10). The lower half of this section consist s of interbedded gray, pink buff and white micaceous clays inter.calated with thin lentils of yellowish sand. This lower half is the Citronelle fonnation and i s separated by an eros . iona l unconformity as well as litholo gically from the Pleistocene . above. The Pl_ eis.tocene consists of yell _ ow and brown cross-bedded _ sands wit}:I some silt. Similar exposures exhibiting the satne features n1ay be seen at Gull Point, Red Bluff, and at J\1agnolia Bluff on Escan1bia Bay east of the city of Pensacola. The clay deposits now being worked at Quintette and J\1olino are probably Citronelle . These are gray to brown in color, dense, and highly plastic. In the vicinity of Pensacola the Citronelle clays are thin and variable in late . ral extent being interbedded, and even cross-bedded, with sands. These clays have been formerly used for stoneware in a pottery in Pensacola and are now being used in a pottery in St. Petersburg. Citronelle clays are also exposed at severa l points northwest of Pensacola, near Muscogee and along the Perdido River. . Berry1 says the physiography and during the deposition of the Citronelle seditnents may be compared with that of the present time along the east coast of Florida north of latitude 28 degrees, or along the Gulf coast w.est of the Ocklocknee River. He says: "We may picture a more or less straight series of barrier beaches, probably with active sand dunes, a mile or more in width, and broken in places by inlets. Back of these beaches there were wide lagoons, of variable width, perhaps not less than a mile and certainly reachi .ng a much greater width where some river expanded into a broad estu . ary, with its shallow and muddy bayous. The water in the lagoons varied from fresh to salt according to the pres ence or absence of inlets and the positions of the rivers." The Lafayette formation (Pliocene) is not known definitely to exist in Florida, but some of the sands and clays of north and west Florida may represent this formation. The beds of recognized Pleistocene age are the Fort Thompson Beds, Lostinans River Limestone, Key West Limestone, Key Largo lBerry,' E. W., The Flora of the Citronelle Formation, U. S. Geol. Survey Prof. Paper 96 , p. 194, 1917 . 

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A PRELIMINARY REPORT ON CLAYS OF FLORIDA 11'/ Limestone, Miami Oolitic Limestone, and the Beach Limestone, and are found in the extreme southern portion of the . peninsula. No known clay deposits are associated with them. There are many alluvial and lacustrine deposits of clay and clay bearing sands throughout the State. These are principally Pleistocene and Recent, yet a few of them may have been for med during the Pliocene period. These deposits tie chiefly along the floodplains of the larger. streams. . Extensive flood-plain deposits are found in the valley of the St. Johns River extending from Vol usia County to Jacksonville . Many of these cla y s have never been worked and many more of them are capable of being utilized for various grades of structural materials. Former brick plants have been located near DeLand, DeLeon Springs, Denver, Palatka, _ Rice Creek, and Middleburg. Most of the clays found in this region are sandy, but some of great purity are found. Similar deposits are found in the vicinity of l(ings Ferry. On the Ocklocknee River two brick plants ( Ocklocknee Brick Co. and Tall::thassee Pressed Brick Co.) now in operation, are using flood-plain clays. On the Apa lachicola River several deposits of good quality are known and one of them is being worked at Blountstown. The sedimentary kaolin found in several points in central Florida is of uncertain age. It will be more fully in a subsequent chap ter. Numerous lacustrine deposits will be discussed in the detailed description o deposits in the following chapter. CONDITION S OF SEDIMENTATION AND SOURCE-S OF MATERIAL A complete geologic understanding of the clays of Florida involves a study of the geology of adjoining states. It also involves a review of the geologic processes that have been operating in Florida through the evidences by which these processes have been interpreted. Clay is always a secondary l?roduct; that is to say, it is always the result of decomposition and disintegration of pre-existing rocks. Igneous rock is the ultimate source of all other rock and therefore is the primary source of all clays. No igneous rocks are known to occur in Florida and in of the geologic conditions under which the Floridian land mass was formed, the probabilities of encountering igneous rock at any reasonable depth 

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118 FLORIDA GEOLOGICAL SURVEY-15TH ANNUAL REPORT ... are practically nil. The s ource of the material forming the clays and other sediments must be sought elsewhere . During the Eocene and Oligocene periods the sediment$ were marine, representing shallow-water deposition and were formed prob ably while all of Florida and the coastal plain sections of Georgia and Alabama were yet subtnerged. These formations were deposited under conditions which were uniform over wide areas. The Floridian penin s ula partially emerged from the sea early in the Miocene period. Erosional forces set at once to and alter the configuration of the then existing surface. Solution of the under lying lime s tones and the resultant formation of sinks also began about this time, affording dep,res si ons for the accummulation of lacustrine deposits. Thus conditions very similar to tho s e existing today began and have continued with but little change to the present time. As deposits of transported clay may differ in thickness, character, and extent, according as the material has been deposited in flood-plains, lakes, swamps, estuaries or the open sea, corresponding variations are found in the Florida clays. Cla y s deposited in the shallow sea or tidal marshes are usually widespread and more uniform . Thus the Chatta hoochee, Tampa and choctawhatchee clays are fairly uniform over the areas they occupy. Under fluviatile and lacustrine conditions, on the other hand, variations in current and variations in the amount and character of the sediments carried resulting from erosional and climatic conditions, cause deposits of these types to differ widely in character. Thus the Alum Bluff, Citronelle and many _ Pleistocene deposits display marked irregularities. . The _ erosion and reworking of formations already de posited has been an important process in Florida. This accounts for the numerous isolated remnants or outliers of formations to be found in the State. 1-\he sedimentary kaolin deposits are an example of this condition. It also accounts for . the presence of one distinct kind of material in two or more formations. Thus phosphatic material has been derived from the Alum Bluff formation, sorted and concentrated in later deposits to such an extent as to make mining profitable. This is also the origin of the Bartow clay. The clays of Florida were derived either directly or indirectly from the crystalline rocks of the southern Appalachians exposed in Ten nessee, North and South northern Georgia and Alabama. 

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A PRELIMINJ\RY REPORT ON CLAYS OF FLORIDA 119 Mate rial resulting from the decomposition and disintegration of this igneou s and metamorphic rock may have been deposited in central Georgia and Alabama as Paleozoic, Me s ozoic or Cenozoic sediments and a second time weathered and eroded away or it may have been transported directly by southward-flowing s tream s to the Florida area. Probably both conditions may be found. In any event, this tnaterial was carried in so luti o n , in suspension in a finely-divided state, or mechanical l y rolled along by the stream currents. The quartz sand and gravel found in many of the clays was r o lled along by mechanical processes, the mica and much of the .colloida l matter was transported in suspen• sion, and much of the lime, magnesia, iron, etc., was probably carried in so lution. The prevailing drainage has been southward in the Southern States, hence most of the sedin1.ents in Florida have been derived from the northern areas. In the case of li mestone residual clay the parent r ock was deposited by precipitation of the calcium carbonate and the deposition of much of the itnpurities from suspensio n where it was being held in a finely divid _ed condition . In the weathering . of a pure limestone no clay would result, but as practically all lime stones are more or le ss itnpure the se insoluble in1purities remain as c la y when the calcium car bonate is dissolved out. Some of the Florida limestones are high in im purities, the r esu lting clay i s quantitatively great. 

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120 FLORIDA GEOLOGICAL SURVEY-I 5TH ANNUAL REPORT -._., ... ___ _ X Purtv" ', v ,Gl ; • : N .-...... MAP OF' • FLORIDA S How•NG LocATION OF" D 8RIC.II, 4•DTIL[ PLMH5 () PoTTERIES 0 SEDIMENTARy KAOLIN MINES 6 FoLLRsEARTt1 MlllltS COMMO .. CLAJS TESTED e .S ao,.,I:NUII7 KAOLIN Oc.cuARfNCfS a ., """•' 0 .. .,. .. ,. H OJII1C_$_ ----. ., I 1.-m: m : o•"'UOJ41 I ' 1 WAs•u"" Jo"' 1----.--.----1 I I I FIG. 2. "j () 0. wtNoqr 1------1 I ; I I I , _____ ..,! • COLli( I\ For explanation see opposite page. 

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A PRELIMINARY REPOR'l' ON CLAYS OF FLORIDA KEY TO MAP (FIG. 2). FULLER'S EARTH MINES. 1. Floridin Company, Quincy, Gadsden County. 2 . Florid in Compan y, J amieson, Gadsden County. 3. Fuller's Earth Company, Midway, Gadsden County. 4. Attapulgus C lay Company, Ellenton, Manatee County. 5. Manatee Fuller's Earth Corporation, Ellenton, Manatee County. BRICK AND TILE PLANTS. 1. Macmillan Brick Company, Molino, Escambia County. 2. Dolores Brick Company, Molino, Escambia County. 3. Barrineau Brothers, Quintette, Escambia County. 4. Allentown Consolidated School, near Milton, Santa Rosa County. 5. Glendale Brick Works, Glendale, Walton County. 6. Murphy Brick Company, Argyle, Walton County. 7. Hall Brick Company, Chipley, Washington County. 8 . Florida Industrial School for Boys, Marianna, Jackson County. 9. Guilford Brothers Brick Company, Blountstown, Calh oun County. ' 1 0 . Tallahassee Presse d Brick Company, Havana, Ga<;isden Co unty. 11. Ock l ocknee Brick Company, Ocklocknee, Gadsden County. 12. Callahan Brick Company, Call a h an, Nassau County. 13. Gambl e and Stockton Company, Sout h Jacksonville, Duval Cou nty . ..,... 14. Clay County Steam Brick Company, Green Cove Springs, Clay County . ....,. 15. Campville Brick Company, Campvill e, Alachua County. V"" 16. Keystone Brick Company, Whitney, Lake Co unty. ""' 17. Morris and Blumer Brick Company, Brooksville, Hernand o County. V"" POTTERIES. 1. Orlando Pottery, Orland o, Orange County. 2. Florida Pottery, St. P etersburg, Pinellas County. 3. Manatee River P otte r y, Bradentown, Manatee County. SEDIMENTARY KAOLIN MINES. 1. Edgar Plas tic Kaolin Company, Edgar, Putnam County. 2. Florida China Clay Company, Okahumpka, Lake Cou nty. 3 . Lake County Clay Compan y, Okahumpka, Lake Co un ty . Fie. 3 .-General View, Campville Brick Co . , Campville, Alachua County. 121 

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122 FLORIDA GEOLOGICAL SURVEY-15TH ANNUAL REPORT CHAPTER VIII DISTRIBUTION AND DESCRIPTION OF DEP01SITS BY COUNTIES A description of the individual clay deposits with reference to their extent, properties and uses was not included in the foregoing account of the clay-bearing formations, inasmuch as the various deposits differ widely in their characteristics. The fuller's earth and "sedin1entar.y kaolin" each occur in severalloealities in the State and a more detailed account of the occurrence of the latter is given in Chapter IX. The various kinds of clay are not confined to any one geographical or political unit, but for convenience be treated here b y countie?. The location of. the active clay-working plants (including fuller's earth) is shown on the accompan ying outline tnap (Fig. 2). ALACHUA COUNTY Alachua County is located in the north central part of the peninsula and the Alachua, Alum Bluff and Ocala formations occupy greater part of its area. Numerous lacustrine and sink-hole deposits of uncertain age are also present, but are lin1ited in extent. Cla y s are of wide spread occurrence, but are usually san. d y in character. . Coarse sandy clay suitable for sand-clay road metal is abundant in the eastern part of the county in the vicinity of Hawthorne. It ranges from five to fourteen feet or more in thickness and is overlain by a loose sand and soil overburden ranging from three inches to three feet in thiclrness. Clay suitable for drain tile, hollow block, fireproofing and a good common brick is found underlying a rather extensive area in the region about Camp"Yille. Except for the color of burned clay, which is pink at cone 010 and a dirty yellowish brown at cone 9, it would be desirable for face brick. The Campville Brick plant, located at abotit one-half mile north of Campville, uses this clay in the manufacture of brick. The plant is located on the Seaboard Line R9-ilway (Tampa Division), which offers shipping facilities to the principal points in south Florida. For a section of pit see page 11 4. The Campville brick is used to some extent for fire-box and furnace linings. It has a good refractoriness and withstands sudden changes 

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A PRELIMINARY REPORT ON CLAYS OF FLORIDA . 12 3 in temperature when in use fairly well without excessive losses from cracking. . A mixture of equal parts of the upper white clay and the lower red dish clay in this deposit as used by the Campville Brick Company has the following physical properties : Physical Properties of Campville Brick Company Clay (Lab. No. b-52). Plasticity, judged by feel............ Excellent. Water of plasticity . . . . . . . . • . . . . . . . . 27.45%, Pore water . . . . . . . . . . . . . . . . . . . . . . . . . 2.55% I Shrinkage water ..... . . • . . . . . • . . . • 24.90%. Linear air shrinkage ............. . . U.S % . Volume air shrinkage . . . . . . . . . . . . . . 28.3 % Modulus of rupture, average .•...... 400.2 pounds per square inch. Slaking test ............ .•...•.. . . • ' 24 hours. Fire tests: Temperature. Linear Slzr. Absorption. Porosity. Per Ce'nt. Per Cent. Per Cent. Color .. 9S0C. 0.5 14.69 33.20 Pink . 1050 0.5 15.81 33.60 Light pink. 1150 1.0 13.79 32.40 Light brown. 1190 1.0 13.66 30.20 Yellowish brown. 1230 1.0 12.40 29.40 Yellowish. 1310 1.0 13.28 30.10 Yellowish. In the northeast part of' the county in the region about Waldo and a brown sandy jointed clay is expqsed in numerous places. It is only for a low grade of common brick. A blue-gray jointed clay is exposed in Hatchett Creek at the cross ing of the Seaboard A ' ir Line . Railway (Cedar Key Division). This clq.y has an airand fire-shrinkage cracks slightly in firing. It is of little value for fired products, except perhaps a poor grade of . common brick. Its physical are: . Plzysicai Properties of H atclzett Clay (Lab. No. 0-47 ).. judged by feel. . . . . . . . • . . • Poor. Water of plasticity .•.......•..•. ..• 39.30% Pore water ......... . . . . . . . . . . . . . . . 3.08% Shrinkage water . : ... •...•.•.•.•.• : 36.22% . Linear air shrinkage. . . . . . . . . . . . . • . • 15.5 % Volume air shrinkage . . • . . . . . . . . . . . • 44.7 % Modulus of rupture, average-. . . . . . . 208.3 pounds per square inch. Slaking test . . . . . . . . . . • . . . . . . . . . . . . 2 minutes. Steel hard at cone 1 . . Fire tests: T Linear Slzr. Absorption. Porosity. Color. Per Cent. Per Cent. Per Cent. 950C. 6.5 8.42 20.50 Pink. 1050 7.5 9.57 21.75 Light brown. 1150 8.5 6.89 18.30 Dark brown. 1190 9.5 1.93 16 .50 Brown. 

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124 FLORIDA GEOLOGICAL SURVEY-15TH ANNUAL REPORT A brown sandy clay occurs in numerous places in the region just west of Gainesville. Here the clay at times imn1ediately overlies the Ocala limestone and at other times is underlain by a sand. It can only be used for a low-grade, soft, porous common brick. A common-brick plant was formerly about two miles northwest of Gainesville. A sample .from the property of D. J. Richbourg, four n1iles southwest of Gainesville, has the following physical properties : Physical Properties of D. J. Richbourg Clay (Lab. No. 0-45). Plasticity, judged by feel ....... . . . . W f , .. ater o p.astictty ............... . Linear air shrinkage .............. . Volume air shrinkage ............. . Modulus of rupture, average . . . . . ... . Slaking test ...................... . Fire tests: Temperature. Linear S!Jr. Absorption. Per Cent. Per Cent. 950 C. 1.0 15.07 1050 1.5 16.44 1150 1.5 15.77 1190 2.2 15.67 Fair. 23.90% 4.5 % 22.55% 255.4 pounds per square inch. 5 minqtes. Porosity. Color. Per Cent. 36.10 Brick red. 34.10 Brown. 33.90 Brown. 32.40 Chocolate brown. Some residual clays from the Ocala lin1estone occur in the southwest portion of the county. These warp and crack badly and hence are prac tically unusable. BAKER COUNTY Baker County is located in the northeast part of the State. The surface n1aterials consist of y ellow and browni s h sandy days and sands, with the Alum Bluff fo:mation underlying n1uch of this loose material. The cla y s are of little value from a comn1ercial standpoint. A clay which occurs about a half-mile southeast of Macclenny on the Maxville road was forn1erly used for comn1on brick, but only a soft, porous, sandy common brick can be made fron1 it. Its phy s ical pr0perties are: Physic.al Properties of Macclenny Clay (Lab. No. <.' ). , Plasticity, judged by feel ........... . Water of plasticity ............... . Pore water ...................... . Shrinkage water .................. . Linear air shrinkage .............. . Volume air shrinkage ............. . Modulus of rupture, average ....... . SJ aking test ...................... . Excellent. 21.40% 0.38% 21.02% 7.1 % 15.6% 105.2 pounds per square inch. 1 hour. 

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1 26 FLORIDA GEOLOGICAL SURVEY-15TH ANNUAL REP ORT Frc. 4 .-Clay pit. Guilford B r ick Company, Blountstown, Calh o un County . The clay is allowed to weather for a time before be ing used. Frc. 5 . M ethod o f stacking a kiln for burning. Guilford Bros. Brick Company, Blountstown, Calhoun County. 

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A PRELIMINARY REPORT ON CLAYS OF FLORIDA 127 clays are comtnon along the Apalachicola R iver, one such deposit being worked by the Guilford Brothers Brick Company at Blountstown. The Guilford Bros. plant is situated one-half 111-ile south of B lount s town on . a spur of the Marianna and Blountstown Railroad and about one-half mile from a barge landing on the Apalachicola River. Thus both rail and water shipping facilities are afforded. The deposit is overlain : by soil averagirigabout six inches in thick ness and is underlain in places by sand . The deposit is ?Omewhat lentic ular, but averages fron1 foul;" to nine feet in thickness . The clay is dug awa y fron1 the p i t face, then heaped up and allo wed to weather for an in definite time. Sand and mica are present in this clay to a slight extent. The clay is at present being used for the tnanufacture of common brick and at the time the field work was being carried . on, brick from this plant was being used in the of the Post Office Building at Apalachicola. This clay n1ay be used for face or common brick, drain tile, hollow blocks, flower pots, turpentine cups, ballast, etc. It has the following properties : Physical Properties of Guilford Bros. Brick Company Clay (Lab. No. o-6). Plasticity, judged by feel ...... . . . . . . Excellent. Water of plasticity . . . . . . . . . . . . . . . . . 29.75% Pore water . . . . . . . . . . . . . . . . . . . . . . . . 0.9 3% Shrinkagewater . . . . . . . . . . . . . . . . . . . 28.82% Linear air shrinkage . . . . . . . . . . . . . . . 9.7 % Volume air shrinlcage . . . . . . . . . . . . . . 32.20% Modulus of rupture, average. . . . . . . . 421.7 pounds per square inch: Slaking .................... 30 hours. Steel hard at cone 1. Overfires at cone 16. Fire tests: Temperature. Linear Shr. Absorption. Porosity. Color. P e r C e nt. Per Cent. Per Cent. 950C. 0.3 17.10 34.00 Brick red. 1.050 0.3 18.20 34.60 Brick red. 1150 7.3 11.30 26.20 Brick red. 1190 7.3 6.50 18.50 Brick red. 1230 7.3 6.35 " 16.80 Brick red. 1310 7.8 4.23 16.40 Chocolate. 1370 7.8 3.42 13.10 Chocolate. 1430 7.8 3.82 14.40 Chocolate. 

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1 28 FLORIDA CEOLOGIC ! \.L SURVEY-I 5'l'li J\ NNUJ\L REPORT Frc. G.-Unloading a kiln. Guilford Bros. Brick Company, Blountstown, Calhoun County . CHJ\RLO'l'TE COUN'l'Y Charlo tte County i s situated in south Flo rida we t of Lake Okee chobee. Sands , n1arls and shell beds occupy the surface ex p osures, but no cla y depo s it s are known at the present time. CITRUS COU NTY Citrus County i s s i tuated in the Hard Roc k Phosphate region and i s underlain mainly by Eocene and Pleistocene formations. Resid ual cla ys occur locally on the phosphate formations , but they are ve r y irregular in thicla1es s and extent and are subject to excessive crackin g and warping in drying due to high air-shrinkage, hence a r e of n o valu e for manufacturing purposes. • CLAY COUNTY Clay County lie s in the lower part of the St. J ohns River valle y and the eastern half of the county is exten sive l y underlain b y floo d-plain cla ys. The western half of the county is covered b y thick deposits of coarse sand with a clay content ranging fron1 15 to 4 0 per cent, much of w hich is su it able for s aQd-clay road metal. The St. Johns River valley clays have been u s ed in nun1 e rous place s for common brick, and one plant n ow operating at Green Cove Springs u ses one of the flood-plain 

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A PRELIMINARY REPORT ON ' CLAYS OF FLORIDA 129 FIG. 7.-Black Creek Barge Landing, near Middleburg, Clay County. Formerly used for shipping brick. Dismantle d kiln may be seen on extreme right. clays. Some calcareous and phosphatic cla ys occur in the southwestern portion of the county . A clay exposed in the vici ni ty of Doctors Inlet in the northern pa.rt of the county and underlying seve ral square miles between the A tlantic Coast Line and the St. Johns River has good dry strength and color, but has a high air-s hrinkage . It may, ho wever, be used for a good grade of comn1on brick, drain tile, hollo w b l ock s, etc. The exact thickne ss of this deposit was not determined , but i s known to be over six feet in places. It is. overlain by sand and loam ranging from one to two feet. A sample of th i s clay taken bes i de the Green Cove Springs-Jacksonville highway, about one-half mi le ea s t of Doctor s Inlet station, has the following physical properties : P!Jysical Properties of Doctors Inlet Clay (Lab. No. o-so). P l asticity, judged by feel ........... . Water of plasticity ............... . Pore water .................... . . . . Shrinkage water .................. . Linear a i r shrinkage. ............. . Volume air shrinkage ............. . Modulus of rupture, average ....... . S laking test ............ .......... . Steel hard at cone 1. Over.fires at cone 9. Excellent. 32.25% 2 .31% 29.94% 14.8 % 36.6 % 504.2 p ounds per square inch. 10 minutes. 

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130 FLORIDA GEOLOGICAL 'suRVEY-15TH ANNUAL REPORT Fire tests: Temperature. Linear Slzr. Absorption. Porosity . Color. Per Cent. Per Cent. Per Cent. 950C. 1.2 6.60 18.40 Brick red. 1150 2.7 5 .69 17.10 Brick red. 1050 2.7 7.22 17.90 Brick red. 1190 4.2 3.69 17.20 Brick red. 1230 5.7 3.04 16.10 Brick red. A day similar to the Doctors Inlet clay is exposed on Black Creek about two miles east of Middleburg on the property of Frank Mooney. A brick plant formerly at this place was only abandoned about ten years ago. and one kiln and parts of the distnantled machinery are still stan.ding at the yard. This plant was located at a barge on Black Creek where tidewater shipping facilities are available. Ship ment was formerly made by barge to Jacksonville and other points on the St. Johns River . The clay pit is situated about" one-half mile northward from the site of the plant. From six to ten feet of clay are exposed. This is overlain by from one to three feet of soil and sand. The clay underlies a part of the adjoining property owned by the Bryan Jennings Artesian Fart;n Land Company. This Middleburg clay also }:las a high air shrinkage, but is suitable for face brick, _ common brick, drain tile and hollow ware. A sample taken from the unweathered portion of the old pit has the followi .ng physical properties : Physical Properties of tlze Middleburg Clay (Lab . No. o-78). Plasticity, judged by feel. . . . . . . . . . . . Excellent. Water of plasticity . . . . . . . . . . . . . . . . 27.90% Pore water . . . . . . . . . . . . . . . . . . . . . . . . 2.07% Shrinkage water . . . . . . . . . . . . . . . . . . . 25.83% Linear air shrinkage. . . . . . . . . . . . . . . . 12.5% Volume air shrinkage. . ............. 41.5% Modulus of rupture, average. . . . . . . . 585.3 pounds per square inch. Slaking test . . . . . . . . . . . . . . . . . . . . . . . 10 minutes. Steel hard at cone 010. Overfires at cone 9. Fire tests: Temperature. 950C. 1050 1150 1190 1230 Linear Slzr. Per Cent. 2.5 3.5 3.5 5.5 5 . 5 Absorption. Per Cent. 8.49 2.82 2.33 1.63 1.38 Porosity. Per Cent . 18.90 9.65 7.68 6.00 4.5o Color. Brick red. Brick red. Gray. Gray. Chocolate brown. 

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A PRELIMINARY REPORT ON CLAYS OF FLORIDA 131 The Clay County Brick Company's plant located in the north edge of Green Cove Springs, works a deposit of gray and red mottled, plastic, slightly sandy clay, the presence of which has been proven under about thirty-five acres and probably underlies an even larger area . It varies fron1s ix to ten . feet in thickness, has an overburden of loose sand and soil, and overlies a dean, white, sharp sand. The sand underlying the clay is used in cement and concrete construction work in Green Cove Springs . This clay is desirable for common brick and drain tile. A sam ple taken from the pit face as worked has the following physical proper ties: Physical . properties of the Clay County Steam Brick Company's Clay (Lab. No . o-.f.J). Plasticity, judged by feel ... ........ . Water of ... . ....... .... . Linear air .shrinkage ............... . Volume air shrinkage .............. . Excellent. 25.75% 10.02% 31.55% . Modulus of rupture, average ....... . Slaking test ...................... . 513.2 pounds per square inch. 1 'hour. Fire tests: Temperature. 950C. 1050 . 1150 1190 1230 1310 Linear Shr. Per Cent. 0.2 0.2 0.2 0.3 0.8 0.8 Absorption. Per Cent. 13.32 , 14.31 11.89 11.96 11.06 11.03 Porosity. Per Cent. 30.95 31.50 28.50 . 28.45 22. 75 20.50 Color ; Grayish pink . Gray. Gray. Gray • Gray. Gray. A clay collected by l\1r. George T. Lloyd, from 'SE}i Sec. 11, T. 7 S., R. 24 E., is suitable for soft, porous, com!f1on brick. Its . physical properties are : Physical Properties of Lloyd Red Burning Clay (Lab. No. o-64). Plasticity, judged by feel. . . . . . . . . . . . Excellent. Water of plasticity . . . . . . . . . . . . . . . . 24.20% Pore water . . . . . . . . . . . . . . . . . . . . . . . . 1.07% Shrinkage water . . . . . . . . . . . . . . . . . . . 23.13% Linear air shrinkage....... . . . . . . . . . . 10.00% Volume air shrinkage............... 30.20% Modulus of rupture, average. . . . . . . . ,565.4 pounds per square inch . Slaking test . . . . . . . . . . . . . . . . . . . . . . . 1 hour. Fire tests : Temperature . 950C. 1050 1150 1190 1230 1310 Linear Shr. Per Cent . o.o 0.5 1.0 1.0 1.5 2.5 Absorption. Per Cent. 14.01 15.03. 11.72 11.21 . 10.60 10.50 Porosity. Per Cent. 33.00 32.50 28.75 28 . 20 25 .10 29.50 Color . Light brick red. Light brick red. Light brick red. Brown. Gray. Gray. 

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132 FLORIDA GEOLOGICAL SURVEY-15TH ANNUAL REPORT clay sent in by Mr. Lloyd frotn Sec. 2, T. 8 S., R. 23 E., contains much coarse, sharp angular quartz sand, but the sand content is not nearly so high as the :n the s edimentary kaolins which occur in this general Mica is also prese n t in small an1ounts. If washej, this clay would be suitable for some grades of white ware. The high porosity listed below is due to sn1all, cracks whicp developed in . the test pieces during fir:ng. A sample of crude clay has the following physical properties: ' Physical Properties of Lloyd W IJite Clay (Lab. No. o-66). Plasticity, judged by feel. . . . . . . . . . . . Excellent. Water of plasticity . . . . . . . . . . . . . . . . 21.50% Pore water . . . . . . . . . . . . . . . . . . . . . . . . 2.85% Shrinkage water . . . . . . . . . . . . . . . . . . . 18.65 % Liriear air shrinkage. . . . . . . .. . . . . . . . . 9.3% Modulus of rupture, average. . . . . . . . 120.4 pvunds pexsquare inch. Slaking test ........... ; . . . . . . . . . . . 3 days. Steel hard at cone 9. Fire tests: Temperature. 950C. 1050 1150 1190 1230 1310 1370 1410 Linear Shr. Per Cent. 3.2 3.7 3.2 3.2 3.7 8.7 12.2 14 . 7 Absorption. Per Cent. 32.07 32.97 29.67 29.60 30.09 19.60 12.53 9.38 Porosity. Per Cent. 48.80 48 .75 45.10 46 . 00 45.65 37. 10 28 .75 21.20 Color. White. White. White. . White. White. White. White. White. Still another white-burn ing clay sent in by Mr. Lloyd fron1 . Sec. 2, T. 8 s .,' R. 23 E . , has a tnuch greater percentage of sand and mica. It has the following physical properties : Physical Properties of Lloyd Sandy White Clay (Lab. No. o-65). Plasticity, judged by feel . . ......... , Poor. Water of plasticity . . . . . . . . . . . . . . . . 18.30% Pore water . . . . . . . . . . . . . . . . . . . . . . . . 0.30% Shrinkage water ............. ...... 18.00% Linear air shrinkage ....... . . . . . . . . . '2.5% Modulus of rupture, average... . . . . . 73.0 pounds per square inch. Slaking test . . . . . . . . . . . . . . . . . . . . . . . 2 minutes. Fire tests: Temperature. Linear Shr. Absorpti on. Porosity. Color. Per Cent. Per Cent. Per Cent. 950C. 0.2 17.90 37.50 White. 1050 1.5 17.04 37.60 White. 1150 1.5 17.49 37.20 White. 1190 1.5 16.90 35.25 White. 1230 2.0 16 .85 32.60 White. 

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A PRELIMINARY REPORT ON CLAYS OF FLORIDA 133 COLUMBIA COUNTY Columbia County lies in the northeastern part of the State. The Alum formation exposed at the surface .in the northern two thirds of the county and the Ocala formation in the southern one-third. Sandy surface clays of uncertain age cover a large part of the county. In some localities this material is clesirable for sand-clay road material. South of the region about Lake City no clays of value are known as is also the case in the north and northeastern parts of the county. About six miles northeast of White Springs a very soft white shale is exp<?sed on the Hamilton County side qf the Suwannee River. For a detailed de scription of this exposure see page 165. . This cla y no doubt underlie s adjacent portions of Colun1bia County as well . . A green jointed clay overlain by four feet of brown, gray and whlte mottled sandy clay is exposed about two miles south of Lake City on the Gainesville road. The contact . between these two clays is indistinct and the upper portion is probably a residual mantle. The thickness of the lower clay is unknown. It has a air shrinkage and cracks badly in drying and is therefore unsuited for use in n1anufactured products. region between Lake City and White Springs is underlain by one or more beds of a greenish jointed clay. These beds are variable in thickness and are interbedded with sands and sandy clays. In places this clay contains calcareous concretions and in other places it contains some phosphatic material, it has a high air shrinkage, warps and cracks badly, and its plasticity is too low to wcrrk satisfactorily in a stiff mud n1achine. For a t y pical section of this clay see page . 114. At abrick plant for11).edy operated about three miles southwest of Lake City a gray sandy clay occurs and was formerly used for common brick. Its low plasticity, low bonding strength aiJ.d poor working quali ties make it undesirable for any kind of manufactured clay product. It is still distinctly soft and porous at cone 15. It has the following physical properties : Plzysical Properties of Lake City Brick Yard No.1 Clay (Lab. No. o-36). Plasticity, judged by feel ............ ' Water of plasticity •............•.• Pore water . .... . . . ......... ....... . Shrinkage water .................. . Linear air shrinkage ............... . Volume air shrinkage .............. . Modulus of rupture, average ....... .. Slaking test .... .. : ........ ....... . Poor. 17.45% 0.23% 17.22% 3 .6% 7.92% 121.0 pounds per square inch. 30 hours. 

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134 FLORIDA GEOLOGICAL SURVEY-15TH ANNUA L REPORT Fire tests: Temperature . Linear Shr . Absorption . Porosity . Color. Per Cent . Per Cent . Per Cent. 950C . 0.6 15.18 33.60 Cream. 1050 1.1 15.22 34.20 . Cream. 1150 1.6 14.50 33.60 Cream. An9ther brick plant was formerly operated about one-half mile of Lake City where a sandy surface clay was u s ed which likewise is undesirable for any burned except a very low grade of com mon brick . A bluish-gray clay occurs on the property of W. N. Cone about four miles north of Lake City on the Benton Road. plasticity is fair, its air shrinkage high, and its general qualities poor. It however, a high modulus of rupture, but is nevertheless undesirable for. burned products . It has the following physical properties . : Physical Properties of W. N. Cone Clay (Lab. No . o-15). Plasticity, judged by feel .. . . . . . . . . • Fair: Water of plasticity . . . . . . . . . . . . . . . . 41.20% Linear air shrinkage. . . . . . . . . . . . . . . . . 14.7 % Volume air shrinkage . .... . .-. . . . . . . . 46.2 % Modulus Qf rupture, average........ 1075.3 pounds per square inch. Slaking test . . . . . . . . . . . . . . . . . . . . . . . . 15 minutes . . Steel hard at cone 010 . Overfires at cone 1. Fire tests: Temperature . 950C. 1050 1150 Linear Per Cent . . 6.3 -7.8 8.3 Absorption. Per Cent. 5.54 4.go 3.58 Porosity. Per Cent. 25.75 24.25 22.25 DADE COUNTY Color . Brick red. Brick red. Brick red. Dade County is situated in the extreme southern portion of the State and its surface formations .consist of limestones, sands and m arls. No cla y s of importance are known. DESOTO COUNTY De Soto County lies in the south central portion of .the peninsula. The surface materials consist of. sands,' marls and sandy clays . Good sand-clay material is abundant in the northern part of the county. A white clay high in lime and tnagnesia occurs a few miles northwest of Arcadia extends through Manatee County to the vicinity of Bradentown . Its lime content gives it a short firing range 

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A PRELIMINARY REPORT ON CLAYS OF FLORIDA 135 and makes it worthless for burned products. For its physical properties see Lab. samples N o s . 0-19 and 07 2 under Manatee County, page 184. The Bartow clay is exposed in the northern portions of the .county. See page 195 fora detailed description of the Bartow clay, Sam-. ple No. 0-53. DIXIE COUNTY Dixie County lies in northern Florida and adjoins the Gulf of Mex ico. N ; o clays other than very loose sandy ones are known in this County. DUVAL COUNTY . Duval County is situated in the lower St. River valley. Some sandy clays suitable only for sand-clay road material occur in the ex treme southwest corner of the county along the Trail Ridge. Flood plain clays are common along the St. Johns River and several of these have been worked in the past for common brick, while one plant at South Jacksonville is now engaged in the production of structural from two beds of these clays. Two clays are expo s ed in the Gamble and Stockton Brick and Tile Company ' s plant at the end of I-Iendricks Street in South Jacksonville. A section of the deposit is as follows: Sand, loo se, brown .................... . . . ........ . .......... . Clay, red mottled ....................... .................... . Sand, w h.i te ......... ....................................... . . Clay, blue, very plastic ................................ ... .... . 2 feet 8 feet 2 feet 10 feet plus The exact depth of this lower clay is not known as the workings have not reached the bottom. The loose brown surface sand at the top of the section is removed by a scraper. The white sand is mixed _with .the red and blue clays to reduce shrinkage and the two clays are used in equal proportions. This deposit is now being used for the production of common and face brick, interlocking hollow block tile, and drain tile. The ware is molded in a stiff mud end cut machine and burned at cone 3 in circular down-draft kilns. Seger cones are used to indicate the progress of burning. 

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136 FLORIDA GEOLOGICAL ANNUAL REPORT Frc. 8.-Clay pit. Gamble and Stockton Brick and Tile Company, 0 South Jacksonville, Duval County. Two different beds of clay separated by a layer of sand are exposed in this pit. The upper red n1ottl ed clay has the foliowing phy s ical properties: PhyJical Properties of Gamble and Stockton Upper R ed Clay (Lab. No. o-58) 0 Plasticity, judged by feel............ Excellent. Water of plasticity . . . . . . . . . . . . . . . . 23.20% Pore water . . . . . . . . . . . . . . . . . . . . . . . . 1.25 % Shrinkage water ................... 0 21.95% Linear air shrinkage............ . . . . 8.7 % Volume air shrinkage............... 24.2 % Modulus of rupture, average........ 608.7 pounds per square inch. Slaking test . . . . . . . . . . . . . . . . . . . . . . . 1 hour. Steel hard at cone 9. Overfires at cone 12. Fire tests: Temperature. 950C. 1050 1150 1190 1230 1310 Linear Sltr. Per Cent. 1.2 1.2 1.3 1.3 1.3 1.5 Absorption. Per Cent. 14.58 15.43 14.73 13.32 12.61 12.63 Poro.1ity. Per Cent. 32.40 33.00 32.60 32.00 27.40 26.60 Color . Brown. Brown. red. Brick red. Brick red. Brick red. 

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A PRELIMINARY REPORT ON CLAYS OF FLORIDA 137 F1c. 9.-Ci rcul ar down-draft kiln. Gamble and S t oc kt on Brick and Tile Co., Sout h Jacksonville, Duval County. The lower b l ue cla y ha s an extremely high modulus of rupture. It ha s a high air shrinkage which i s a disadvantage, but on the other hand it dries easily without warpin g and cracking. It alone can be u sed for face brick, hollow blocks, ro ofing tile, drain tile, etc . It has the fo llowin g physical properties: Physical Properties of Gamble and Stockton Blue Clay (Lab. No. 0-32) . Plasticity, judge d by fee l ...... : . . . . . Excellent. Water of plasticity . . . . . . . . . . . . . . . . 30 .50% Pore water . . . . . . . . . . . . . . . . . . . . . . . . 0.5 1 % Shrinkage water . . . . . . . . . . . . . . . . . . . 29.99% air. shrinkage. . . . . . . . . . . . . . . . 13.0 % Modulus of rupture, average ........ 1 593.1 pounds per square inc h. Slaking test . . . . . . . . . . . . . . . . . . . . . . . 1 hour. Stee l hard at con e 05. Overfires at cone 12. Fire tests: T emperature. 950C. 1050 1150 119 0 1 230 1310 Linear Shr. Per Cen t . 0.5 4.0 9.0 4.0 9.0 4.5 A b sorpti otz. P e r Cent. 13.95 7 .2_1 5.26 3.50 3.25 1.94 P orosit y. Per Cen t . 20.75 20.40 19.8 . 0 15.30 14.20 13.20 Color. Brown. Brick r e d . Brick red. Brick red. Brick red. Brick red. A brown i s h, s andy surface clay from the Platt Bros . brick pla n t, now abandoned, about two and one-half miles east of South Jackson-

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138 FLORIDA GEOLOGICAL SURVEY-I 5TH ANNUAL REPORT ville, was tested by the Bureau of Standards in 19141 • The results of these tests indicate that it n1ay be used for face and cornmc;>n brick, hol low blocks, drain tile, etc. Its physical properties are : Physical Properties of Platt Bt:os . South Jacksonville clay, Bureau of Standards (Sample No . II). PI astici ty ......................... . Water of plasticity ................. . Linear air shrinkage .•............. Fire tests : Temperature. Linear Shr. Per Cent. 0.05 0.827 2.34 Good. 27.4% 6.2% Porosity. Per Cent. " 28.1 990C. 1020 1050 1080 "1110 1140 1170 1200 1230 1260 1290 1320 -. --------. 25.7 25.8 24.8 24.6 22.5 22.5 20.4 16.6 11.5 3.97 7.5 ESCAMBIA COUNTY Red. Red . Red. Red. Red. Red. Red. . Red. Red. Red. Red. Red. Color . Escambia County lies between the Escambia and. the Perdido rivers in the extreme western end of the State. Its surface exposures are chiefly sands and clays of Pliocene and Pleistocen,e age. From the ceramic viewpoint this county is perhaps the most interesting one in the State; its clay deposits are numerous and widely and the . se range in quality from common . brick to stoneware and terra-cotta clays. Face and common brick, turpentine cups and some pottery are now being made from Escambia County clays and a pottery formerly located in Pensacola made jugs and other forms of stoneware from local deposits. Clays from Escambia County have probably been known and used longer than any others in Florida. Clay from Pensacola was shipped to Josiah W in England in 17 6 6 for experimental work in his pottery. Williams3 states that brick were being manufactured -in West Florida prior to 1827 and cargoes of them were being shipped ISellards, E. H . , Report on Clay Tests for Paving Brick, Fla. Geol. Survey Press Bull. No. 7, 1915. 2Meteyard, Eliza, Life of Josiah Wedgewood, Vol. I, p . 471, 1865. 3Williams, John L., West Florida, p. 69, 1827. 

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• l 'i ' 1 FI G . 10.-Biuff on west bank of Escambia River at Dexland, opposite Gonzal es . Interbedde d clays (Citronelle Formation?) in lower h a l f of cliff; Pleistocene sands in upper half.-Courtesy of Chas. A. Dexter. > 1-0 ::0 t:l t"' z > >< t:l 1-d 0 1-j 0 z () r > >< Ul 0 I-Ii I-Ii r o . 0 >: 

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140 FLORIDA GEOLOGICAL SURVEY-I 5TH ANNUAL REPOR'l' weekly to New Orleans from Pensacola . He also states that fire-brick in particular were in great demand and brought a very good price. The sarr:e author, writing in 18 371 , rei t erated the satne conditions. Crary2 ma d e both mud and dry-press brick on Escambia Bay from 1856 to 1860 for the construction of Fort Jefferson on Dry Tortugas Island . He later established a brick plant at Bluff Springs in the north ern p art of E s can1bia County. The san1e author, a in writing of fire-clays, s ays " the be s t developed beds of fire-clay are found in Escatnbia County, . Florida . In fact, the whole is underlain . with one vast indetermin able bed of potter's clay and fire-clay, in strata from six to forty feet deep, often cropping out on the surface . This clay is suitable for all kinds of pottery, for fire-brick, and for the very best kinds of building brick, or blocks for paving, and is cheap, accessible and in every way advan tageously situated for profitable manufacturing." Crary, however, de fines fire..,clay as "antedihivial or primitive clay" .4 The tenn "primitive clay" is here applied to bedded deposits of clay which were not of plain origin. This definition of a fire-clay not now accepted and the clays of Escambia County referred to by Crary are not fire-clays. The Citronelle formation underlies much of Escambia County and in . most places is overlain unconformably by more recent Both the Citronelle formatiop. and the undifferentiated Pleistocene sediments above consist essentially of lenticular, cross-be.dded and interstratified sands and clays. Clays, how . ever, form the greater part of the Citronelle section while . sands prevail in the Pleistocene deposits. . . An erosional unconformity separates the Citronelle formation from the Pleistocene. Other minor unconformities may be observed in numerous places. In a sand-clay pit about five miles north of Pensacola . . on the Flomaton road an unconformity occurs between two cia ys and is marked by a half-inch layer of li!llonite. Layers of limonite, in places as much as . six inches in thickness, are of conunon in several of the clay exposures where they mark the contact between two clays or bet\yeen a sand and a clay . These limonitic layers probably represent zones of concentration formed froin descending waters which have leached out. the iron from the overlying lWilliams, John L., Territory of Florida, p . 114, . 1837. 2Crary, J. W., Sr., Brickmaking and Burning, pp. 14 and 35, 1890. p . 3. 4Same, p. 28. 

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A PRELIMINARY ON CLAYS OF FLORIDA F'rc . 11.-V.iew of a pit face showing cross-bedded clays (probably Pleistocene). Dolores Brick Co., Molino, Escambia County. Ftc. 1 2 .-General v iew of cla y pit (Citronelle Formation?), Barrineau Bros. Brick Co., Quintette, Escambia County. 141 

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142 FLORIDA GEO LOGIC A L SURVEY-15TH ANNUAL REPORT Fr c . 13.-Layer of limonite overlying cross-b edde d sand. The sand i s underl a in b y clay . Barrineau Bros . Brick Co., Quinte tte, Escambia County. ferruginous sediments and in place s the y may n1ar k the upp e r limit of a former ground water table. Chemical analyses of the s e clays are not a vai l ab le and therefore the iron content i s not known, but if any is prese n t , as i s to be expected in clays associated with limonite, its co loring influence i s surprisingly weak. Pink, cream, light buff and gray color s predominate and no typi cal red-burning clays are found, except in the case of those in the vicinity of Molino w hich are not appare ntl y associated with litnonite. Mica i s presen t in sma ll amounts in practically all of the Escambia County clay s observed . A sand-clay mantle, used locall y for road material, overlie s mo s t of the county. Some of the cla ys are qu it e s andy and oth e r s are practi cally free from sa n d. At Magnolia Bluff, Red B luff and Gull P oint , o n Escambi a Bay, and at Dexland Bluff on the E s cambia River, sev eral strata of cla y are e x posed which in their raw state are red , pink, o r gray, but w hich h ave practically the s ame color and qual i tie s whe n burned. Son1e of the s e strata are al s o expos ed in a cut o n the Gulf, Florida and A l abama Railroad about three rhiles east of Mus cogee and near Eleven :rvi ile Creek on the Pensaco la a n d A l abama Railroad ab out ele ven mi l es n o rth w est of Pensacola. These clay s range in thickn ess from a few i nches to 

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A PRELIMINARY REPORT ON CLAYS OF FLORIDA 143 twelve or fifteen feet and are interbedded with sands and sandy clays. Tthin lentils of cla y often appear in the s and. A given stratum of this clay -may be distributed over a wide area, yet. it may not be continuous throughout this region. Its thickness may vary and in places it tnay di s appear altogether, owing at time s to non-deposition, out in mos t place s to subsequent erosion. The following section at Gull Point will be illustrative of the gen eral region, but it is to be noted that the intervals between the various strata are variable : . . Sedion at Gull Point, Escambia Bay. Soil ...... ........... .............................................. . 2 feet. 4 feet. 4 feet. 3 feet. Clay, gray, jointed, Gull Point No. 1 (Lab. Sample No. 0-49) ........... . Sand, cross-bedded, with some clay lentils ............................ . Clay, gray, very plastic, Gull Point No. 2 (Lab. Sample No. 0-2) ........ . Sand, cross-bedded, with clay lentils ................................. . 10 feet. 4 feet. ? Clay, red, very plastic, Gull Point No. 3 (Lab. Sample No . 0-31) ........ . Sand, cross-bedded, with some clay .lentils ............................. . A boring made near Ninth Avenue and Marino Street in the City of Pensacola indicated the following section : Section near Nintlz Avenue and Marino Street, Pensacol(J. Soil and sand ............. . ................................ . Clay, gray, very plastic ..................................... . Clay, red, pI as tic ....................... .................... . Glay, gray, sandy .. ........... 4 •••••••••••••••••••••••••••• Clay, red, plastic ........................................... . s and, red ...... ............ ................................ . Sand, white ................................................ . 5 feet feet 6 inches 4 feet 6 inches 8 inches ? This section was made at the site of the Kohler Pottery, formerly operated in Pensacola, and is only about two miles frmn the. Gull Point section. The uppermost gray plastic clay was used in the manufacture of jugs and sin1ilar articles of stoneware. This bed is exposed about a half block northeastward in an excavation made by the city of Pensacola and corresp<?nds in appearance arid properties to the Gull Point clay No. 2 (Lab. Sample No: 02) and is probably the same stratum. The Gull Point clay No. 3 (Lab. Sample N(). 0-31) is here split into two thin layers of six inches each -separated by a coarse, gray, sandy clay four feet in thickness. Gull Point clay No. 1 is not exposed here. At Dexland Bluff, property of Chas . A. Dexter, on the Escambia River opposite Gonzales, about ten miles north of Pensacola, a sim ilar 

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1 44 FLORIDA GEOLOGICAL SURVEY-I 5'l'H ANNUAL REPORT F JG. 14 .-Pink pottery clay (Citronelle F ormation?) exp o sed m bluff at Gull Point near Pensacola, Escambia County. Frc. 15.-U nconformity between two clay beds expose d in a pit five mi l es north of Pensacola, Escambia County. 

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A PRELIMINARY REPORT ON CLAYS OF FLORIDA 145 exposure is to be seer:t. There are two bluffs, each about 500 feet long and 65 feet above the river. The northern bluff is termed the Upper Bluff and the southernmost one the Lower Bluff. A generalized section made at the lower end of the Lower Bluff is as follows: Generalized Section near Soutlz End of Lower Dexland Bluff. Sand, cross-bedded with some clay lentils (Pleistocene)............. 30-35 feet Unconformity. erosional, s eparating Citronelle formation from Pleistocene ................ .......... . .................. . . . Clay, gray sandy ............... ............................... . Clay, red, very plastic (Dexland No.2, Lab. Sample No. 0-1 . 8) ...... . Sand parting ............................. ...................... . Clay, gray, very plastic (Dexland No.3, Lab. Sample No. 0-13) ..... . Sand, cross-bedded, containing coarse quartz pebbles ............ . . 10-15 feet 6-8 inches 1-2 inches 2-4 feet ? In this section Dexland clay No. 2 (Lab. Sample No. 0-18) very closely resembles the red clay at Gu11 Point (Gull Point No. 3, Lab. Sample No. 0.31), but contains a slight amount of sand. The Upper Dexland Bluff has essentially the same section as the one just given, with an additional stre1:tum about six feet . above the river level consisting of a black plastic day about six inches in thickness ( Dex land No.6, Lab. Sample No. 0-25). At the upper end of the Lower Dexland Bluff is a ten-foot exposure of a gray mottled plastic clay (Dexland Nb. 1, Lab. Sample No. 0-82) which is probably the same as the Barrineau Bros. clay at Quintette (Lab. Sample No. 0-68) only six or miles farther up the river. It is here, however, not associated with lin1onite. The qualities of these clays are sitnilar, but their raw color, which is lost in firing, is variable. These clays are desirable for terra-cotta, stoneware, grades of pottery and roofing tile. From a commercial point of view, however, the clays exposed on Escambia Bay and at Dexland Bluff, on the Escambia River, offer very little. The beds are thin and variable and are overlain by a heavy over burden which is as much as forty feet in places. Sotne of these clays are now being used in a small pottery in south Florida which specializes in ornamental articles. The amount of clay needed for this kind of demand is not great and can be procured at natural exposures without extensive exca vation. Gull Point Clay No. 1, the gray jointed clay uppern1ost in the sec tion and overlain by only about two feet of soil, has the following physi cal properties : 

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146 FLORIDA GEOLOGICAL SURVEY-I 5TH ANNUAL REPORT Phy$ical Properties of -Gull Point Clay No. I (Lab. No. 0-49). Plasticity, judged by feel ........... . Water of plasticity ............... . Pore water ....................... . Shrinkage water .................. . "Linear air shrinkage ............... . Volume air shrinkage .............. . Modulus of rupture, average ....... . Slaking test .................... .. . Steel hard at cone 05. Overfires at cone 16. Fire tests: Temperature. Linear Slzr. Absorp#on. Per Cent. Per Cent. 950C. 6.7 18.58 1050 7.3 17 . 90 1150 7.0 12 .38 1190 7.2 12.25 1230 7.1 12.54 1310 7.4 9 .41 1370 8.2 6.49 1430 8.2 2 .85 Excellent. 22.95% 0.15% . 22.80% 7.3% 22.9% 246.2 pounds per square inch. 24 hours. Porosity. Color. Per Cent. 35.75 Pink. 34.40 Pink. 28.00 Cream. 23.60 Cream. 23.00 Cream. 22.20 Gray. 21.30 Gray. 13.00 Gray. Gull Point Clay No. 2, the second clay stratum from the top of the section, has the following physical properties : Physical Properties of Gull Point Clay No. 2 (Lab. No. o-2). Plasticity, judged by feel ........... . Water of plasticity ............... . Pore water ....•................... Shrinkage water .................. . Linear air shrinkage ............... . Volume shrinkage .............. . Modulus of rupture, average ....... . Slaking test ...................... . Steel hard at cone 1. Fire tests: Temperature. Linear S lzr. Absorption. Per Cent. Per Cent. 950C. 0.8 27.87 1050 0.8 20.79 1150 5.7 10.45 1190 6.7 5.20 1230 6.7 5.08 1310 6.7 4 .82 1370 6.7 1.92 1430 8.2 1.36 Excellent. 31.75% 0.93% 30.82% 8.3% 28.9% 180 .7 poundsper square inch . 1 hour. Poro$ity. Color. Per Cent. 39.17 Pink. 37.50 Pink. 23.26 Gray. 12.30 Gray. 10.50 Gray. 10 .45 Gray. 7.53 Gray. 7.16 Gray. Gull Point Clay No. 3 lies nearest the bottom of the section. It has a deep, reddish-pink color in its raw state, which it retains when fired at cone 05 but loses before cone 1 is reached. It has the following physi cal properties: 

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A PRELIMINARY REPORT ON CLAYS OF FLORIDA Ftc . 16.-Mining clay with steam s h ovel, Dol o r e s Brick Compa n y Molino, Escambia County. FIG. 17.-Dump car for c onveying clay from pit t o press . Dol o r es Brick Company, Mol ino, Escambia County . . 1 47 ' 

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1 4 8 FLO lUD A SUf , \1EY-I51' H A N N U A L Frc. 18.-Vi ew of dry ing she d showing met h od of stack ing brick for dry ing. D olores Brick Company, Escambi a Coun.ty . Physical P roperties of Gull Point Clay No.3 (f.:ab . No. O -JI) . Plastici ty , judged by fee l ........... . ' 'f.l:T f I . . n ater o p ast1c1ty . . ............. . Pore water .... ................... . S h rin k a ge water ............ ...... . Linear air shrinkage ... ............ . Vo l ume air shrinkage .............. . M o du lu s o f rupture, average ....... . Slakin g t es t ...................... . Stee l hard at cone 1. F ire tests: Exce ll ent. 32.25% 2.6 1 % 29.64% 9.7% 32.8 % 251.5 pounds per square inch. 1 h ou r . T e m pe rature. Linear S lzr. Absorption. Porosit y. Color. Per Cent. P er Cent. Per C ent. 950 C. 1.8 2 1.20 38.40 Reddish pink. 1050 2.0 20.10 36. 70 Reddish p in k . . 1150 4.3 11. 40 24 .50 Choco late brown. 119 0 5.3 6.56 14.90 Choco late brown. 1 230 7.8 4.3 2 10.40 Choco late brown. 131 0 11.3 3.29 7.40 Choco late brown. • Dexl and C l ay N o . 2 i s a thin s tratum , six o r eight inche s, exposed in Lower De xlan d Bluff . It ha s a n appr e c i a b le amount o f quartz sand. Its ph ys ical propertie s a r e : 

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A PRELIMINARY REPORT ON CLAYS OF FLORIDA Physica l Properties of Dexland Plasticity, judged by feel. .......... . Water of plasticity ............... . Linear air shrinkage ............... . Volume air shrinkage .......... . ... . Modulus of rupture, average ....... . Slaking test . .............. ....... . Steel hard at cone 010. Overfires at cone 16. Fire tests: '• T emperatu re. Linear Shr . P er Cent. 950 C. 1.1 1050 1.9 1150 4.4 1190 4 . 4 1230 5.4 1310 5.4 1370 5.4 1430 6 . 4 Absorption. Per Cent. 14.95 14 .30 9 .30 7.83 6.80 5.35 3 .72 3 .32 Clay No. 3 (No. Lab. o-13) . Excell e nt. • 28.60 % 11.6 % 33. 8 % 656.6 pounds per square inch. 2 days. P oro sity. Color. P er Cent. 22.40 Pink. 29.75 Pink. 20.95 Buff. 19.2 0 Buff. 18.30 Cream. 12.10 Cream. 11.70 Gray. 10.80 Gray. 149 Separated from the above clay by a thin sand parting i s Dexland N o. 3, which is a very plastic gray clay having the follo wing ph ysi cal prop erties: Physica l P ropertie s of De:tland Clay No.3 .(La.b. No. o-13). Plasticity, judged by feel . .......... . Water of plasticity . .............. . Pore water ....................... . Shrinkage water : . .... ............ . Linear air shrinkage ............. .. Volume air shrinkage ... ........... . Modulus of rupture, average ....... . Slaking test .......... . ........... . Steel hard at cone 05. Overfires at' cone 16. Fire tests: Excellent. 29 . 40 % 1.65% 27.75 % 10.6 % 38.4% 475.0 pounds per square inch. 20 minutes. T emperatur e . Li1lea r Shr. Absorption. P orosity. Color . Per Cent. P e r Cent. Per Cent. 950C. 0 . 5 16.80 ' 33.65 Pink. 1050 0.6 18. 40 32.25 Cream. 1150 6 . 4 12.25 18.00 Buff . 1190 6.4 4.15 19.45 Buff. 1230 6.4 2 .58 10.10 Gray. 1310 6.4 1.22 5 . 40 Gray. 1370. 6.9 3.05 5.25 Gray. 1430 4.4 6.75 Gray. Dexland Clay No. 4 is a g ray, slightly sandy clay, expose d in both the upper and lo wer bluffs. It i s the uppermo s t clay stratum havi . n g an 

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150 FLORIDA GEOLOGICAL SURVEY-I 5TH ANNUAL REPORT Frc. 19.-Plant and drying sheds , Dolores Brick Co., Molino, Escambia County. Frc. 20.-Drying tunnels. Macmi11an Brick Company, Molino, Escambia County. Waste heat from kilns being fired is used to dry green brick . F'rc. 21.-A battery of circular down-draft kilns. Dolores Brick Co . , Molino, Escambia County. 

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A PRELIMINARY REPORT ON CLAYS OF FLORIDA 151 appreciable thickne ss and ranges from six to fifteen feet. It has the following physical properties: Physical Prop er ties of Dexland Clay No.4 (Lab. No. o-12). Plasticity, judged by feel..... . . . . . . . Excellent. Water of plasticity . . . . . . . . . . . . . . . . 25.20% Pore water . . . . . . . . . . . . . . . . . . . . . . . . 1.37% Shrinkage water . . . . . . . . . . . . . . . . . . . 29 .95% Linear air shrinkage . . . . . . . . . . . . . . . 8.5 % Volume air shrinkage............... 19.4% Modulus of rupture, average. . . . . . . . 207.9 pounds per square inch. Slaking test .. . . . . . . . . . . . . . . . . . . . . . 20 minutes. Steel hard at cone 1. Fire tests: Temperature . L i near Sltr. Absorption. Porosity. Color. Per Cent. Per Cent. Per Cent. 950C. 1.0 18.70 35.25 Cream. 1050 1.0 17.95 34.60 Cream. 1150 1.5 17.50 34.20 Cream. 1190 1.5 13.80 Cream. 1230 1.5 11.58 27.75 Cream. 1310 1.5 10.58 25.20 Cream. 1370 1.5 7.57 25. 90 Brown. 1430 2.5 6.30 20.40 Brown. Dexland No. 5 is a gray plastic clay ranging frotn six to ten feet in . thickne ss and expo s ed about three feet above the river level at the upp e r bluff. Its ph y sical properties are: Physical Properties of Dexland Clay No. 5 (Lab. No. o-73). Plasticity, judged by feel... . . . . . . . . Exceiient. Water of plasticity................. 28.60% Pore water . . . . . . . . . . . . . . . . . . . . . . . . 0.85% Shrinkage water . . . . . . . . . . . . . . . . . . . 27.85% Linear air shrinkage.......... . . . . . . 10.4 % Volume air shrinkage............... 32.8 % Modulus of rupture, average........ 384.4 pounds per square inch. Slaking test . . . . . . . . . . . . . . . . . . . . . . . 10 minutes. Steel hard at cone 010. Fire tests: Temperature. Line ar Sltr. Absorption. Porosity. Color. Per Cent. Per Cent. Per Cent. 950C. 0 . 1 24.30 32 .05 Cream. 1050 1.1 17.20 30.65 Cream. 1150 2.6 9.86 21.50 Brown. 1190 5 . 6 6 . 24 9.70 Brown. 1230 5 . 6 6.16 9.72 Gray. 1310 6.6 4 .08 6.65 Gray. Dexland No. 6 is an eight-inch layer of black pla s tic clay exposed about four feet above the river at the lower end of the Upper Bluff. Its 

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1 52 FLORIDA GEO LOGICA L SUR VEY-I5' l'II ANNUAL REPOR T FIG. V i ew of B arrineau Brc s . B r ;ck Plant, Quintette, Es ca mb i a County . black color is due to the pre s ence of orga nic n1atter w hich is completely burned off, lea v in g it a light-creatn color at cone 010. Its ph y sical prop erties are: Physical Properti e s of Dexland No.6 (Lab. No. o-25) . Plasticity, judged by feel ........... . Water of plasticity .. .............. . Pore water ....... ...... .......... . Shrinkage water .................. . Linear air shrinkage ............... . Volume air shrinkage ........ ...... . Modulus of rupture, average ....... . Slaking test ...................... . Steel hard at cone 010. Fire tests: T emperature . Linear Shr. A b s orption . P e r C ent. Per Cent. 950 C. 0.8 16 .22 1050 2 . 2 16.56 1150 2.2 12.80 1190 3.2 7.82 1230 3.2 7 .95 1310 3.2 6.84 1370 4.2 4 . 72 1430 7.7 3.62 E x cellent. 26.90% 0.40% 2 6.42% . 10.8 % 31.0 % 1021.1 p o unds per square inch. 24 hours. P o r osi ty. Color. Per Cent. 40.50 Cream. 31.75 Cream. 27 .50 Cream. 1 7 .50 Gray. 17.80 Gray. 16.90 Gray. 12.95 Gray. 10. 20 Gray. C l ays ha ving propert i e s s imi lar to the Dexland and Escambia Bay clays are al s o found farther westwar d in the va lley of the Perdido River. A reddi s h-pink, very smooth-textured, highly plastic cla y occurs about three mi l e s ea s t of lVI u s cogee in a cut o n the Gulf, Florida and Alabama Railroad. The cla y i s cro ssbedded and dip s s lightly to the westward. There are s everal strata alternating with thin beds of sand . 

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A PRELIMINARY REPORT ON CLAYS OF FLORIDA 153 This clay is underlain by sand and sandy cla y. The overburden ranges frotn one to six feet. This clay i s free from sand, but contains stnall amounts of very fine mica flakes . Its physical properties are: Physical Properties of Muscogee Cut Clay (Lab. No. 0-4). Plasticity, judge d by feel. . . . . . . . . . . . Excellent. Water of plasticity................. 27 .90% Pore water :. . . . . . . . . . . . . . . . . . . . . . . 0 .68% Shrinkage water . . . . . . . . . . . . . . . . . . . 27.22% Linear air shrinkage ....... . . . . . . . . . 6.4% Volume air shrinkage............... 18.2 % Modulus of rupture, average. . . . . . . . 214.3 pounds per square inch. Slaking test . . . . . . . . . . . . . . . . . . . . . . . 1 hour. Steel hard at cone 1. Overfires at cone 15. Fire tests: Temperature . Linear Shr. A bsorptio1l. Porosity. Color. P er Cent. P er Ce1lt . Per Cent. 950C. 0.9 19 .7 5 36.43 Pink. 1050 0.1 18.32 35.81 Pink. 1150 5.1 9.25 16.58 Buff. 1190 5.1 9.42 14 .2 3 Buff. 1230 5.6 6.50 12.39 Cream. 1310 5.6 5 .30 11.04 Cream. 1370 6.1 0.49 2.17 Gray. 1 430 4.6 1.05 5.41 Gray. On the property of I. L. Schaffer on the Pensaco l a and Alabama Railroad, about e leven miles northwes t of Pensacola, is another exposure of a similar clay . . This is gray and brown mottle d, occurring in a very irregular depo sit overlain unconformably by a cross-bedded sand. The clay underlies an exten s ive area in this loc ality, but is quite variable in thickne ss. In places it is as tnuch as fifteen feet thick. It has the fol lowing physical properties : Physical Propertie s of Schaffer Clay (Lab. No. 0-40). Plasticity , judged by feel. . . . . . . . . . . . Excellent. Water of plasticity................. 26.15% Pore water . . . . . . . . . . . . . . . . . . . . . . . . 0.18% Shrinkage water . . . . . . . . . . . . . . . . . . . 25.97% Linear air shrinkage. . . . . . . . . . . . . . . . 8.3% Volume air shrinkage............... 23.95 % Modulus of rupture, average ........ 262.8 pounds per square inch. Slaking test ........ : . . . . . . . . . . . . . . 30 minutes. Steel hard at cone 05. 

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154 FLORIDA GEOLOGICAL SURVEY-I 5TH ANNUAL REPORT Fire tests: Temperature. Linear Shr. A bsorptiotz. Porosity. Color. Per Cent. Per Cent. Pe r Cent . 950C . 0.8 19.23 35.40 Pink. 1050 1.7 19.90 33.10 Cream. . 1150 1.7 19.45 29.75 Cream. 1190 2 . 7 11.30 24.20 Cream. 1230 2.2 1 0.10 24.60 Gray. 1310 4.2 7.72 21.50 Gray. 1370 4.7 5 .39 1 6.90 Gray. 1430 6 . 7 1.72 4.85 Gray. A dense, gray, plastic clay is of rather widespread occurrence in the region about Quintette. An extension or outlier of \vhat is probably this same deposit is exposed at the upper end of Lower Dexland Bluff. I t underlies both the hill just west of Quintette station and the one about one quarter-mile northward. It was also observed on the property of S . J . Baumeister, one-half mi l e west of Quintette. A section made at t he Barrineau Bros. Brick Cotnpany's plant at Q ' uintette is as follows: S ectio n o f Bar rineau B ros. Brick Compan y Cla y Pit, Quin t e t te. S 'oi I . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 feet. Sand . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 feet. Limonite • . . . . . . . . . . . . . . . . . . . . . . . • 6 inches. C.lay : . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 feet. Limonite • . . . . . . . . . . . . . . . . . . . . . . . . . 2 inches. C}ay, dense, plastic........... 30 feet p l us (variable). L i momte . . . . . . . . . . . . . . . . . . . . . . . . . 3 inches (in places only). Sand ......•...... . ........... . . . ; • ? (in p l aces on ly). In many places the limonite overlies a cross-bedded sand. . The Barrineau Bros.Brick Company use this clay for the manu facture of face and common brick and turpentine cups. Their p lant is l ocated ori the Pensacola Division of the Louisville and Nashville Rail r oad. The product is marketed chiefly in western Florida, southern A labama, Mississippi and Louisiana. Mobile and Pensacola absorb the greate r part of the output. The First Baptist Church in Pensaco l a was bui l t of this brick. This clay may be used for terra-cotta, stoneware, roofing ti l e, flowe r pots, as well as the common structural materia l s. This is not a red-burning clay as would be anticipated from its association with limonite, but a very light-pink at cones 010 and 05 and grades into buff, gray and grayish-brown as the temperature is increased . The physical properties are as follows : 

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A PRELIMINARY REPORT ON CLAYS OF FLORIDA 155 Physical Prop ertie s of Barrineau. Bros. Clay, Quintette (Lab. No. o-68) . Plasticity, judged by feel . .......... . Water of plasticity ............ .... . Pore water ............ . ......... . . Shrinkage water .................. . Linear air shrinkage ............... . Volume air shrinkage .............. . Modulus of rupture, average .. ..... . Slaking test ...... . . . ............ . . Steel hard at cone 010. Fire tests: Excellent. 25.00% 0.38% 24.62% 11.4 % 37.2% 421.0 pounds per square inch. 10 minutes. Temperature. L inear Shr. Absorption. Porosity. Color. Per Cent. Per Cent. Per Cent. 950C. 0.4 12.68 26.45 Cream. 1050 0.6 12.14 25.40 Cream. 1150 1.1 8.88 22.70 Buff. 1190 1.6 8 .31 20 . 00 Buff. 1230 1.8 8 . 22 19.40 Buff. 1310 2.6 5.03 17.00 Gray. 1370 2.6 4 . 62 16. 80 Gray. 1430 3.1 2.54 10.25 Gray. Only about ten feet of this clay are exposed above the river at Dexland Bluff , s ix or seven miles south of Quintette. The deposit, how ever, probably has a much greater thickness. Its physical properties are: Physical Properties of Dexland No. I (Lab. No. o-82). Plasticity, judged by feel........... . Excellent. Water of plasticity................. 27.95% .Pore water . . . . . . . . . . . . . . . . . . . . . . . . 1.30% Shrinkage water . . . . . . . . . . . . . . . . . . . 26.65% Linear air shrinkage ............... . 10.0 % Volume air shrinkage ...... ,........ 30.3 % Modulus of rupture, average. . . . .... 547 . 4 pounds per square inch. Slaking test . . . . . . . . . . . . . . . . . . . . . . . 24 hours. Steel hard at cone 010. Overfires at cone 18. Fire tests: Temperature . Linear Shr. Absorption. Porosity. Color . Per Cetzt. Per Cent. Per Cent. 950C. 0.2 18.43 29 . 20 Pink. 1050 1.5 18.75 32.20 Gray; 1150 2.5 13. 80 27.80 Brown . . 1190 5.0 10.45 22.20 Brown. 1230 5.0 11.07 25.10 Buff. 1310 5.0 7.66 18.70 Buff. 1370 5 . 0 5.74 16.55 Buff. 1430 7 . 5 3.88 12.30 Buff. At Molino two brick plants are now in operation. Both of these are located on the Louisville and Nashville Railroad. The Dolores Brick Company is located about one-half mile and the Pensacola Brick Com-

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156 FLORIDA GEOLOGICAL SURVEY-I 5TH ANNUAL REPORT pany about one mile north of Molino s tation. Th_ e Dolores Brick Com pany has been loc ated here about twenty yea r s, but the Pensacola Brick Company is just completing the erection of its plant and i s now in readi ness to market it s product. The McMillan Brick Company formerly operated a plant about three miles north of Molino. .The clay exposed in thi s localit y is eighty o.r n1ore feet in thickness. Sixty feet of cla y are e xposed in one of the D9lores pi ts and bor _ings twenty feet deep in the floor of workings did not penetrate the bottom . The clay al so extends for a considerable distance northward and west ward. In each exposure at this localit y the clay is cross-bedded and is interstratified with numerou s sa nd laye r s . The sa nd layer s are thin while the clay strata are thick and t:elatively pure . The run of bank is u s ed at both p l ants and the $andy material is thoroughly mixed wit h the pure clay. The raw clay is brownish-gray in color, has good plasticity and working qualities and drie s ea s ily. It is a light, red-burning clay . Both plants u sing thi s cla y make face brick and common brick. Their principal markets are in west Florida and southern Alabama, M _ ississippi and Louisiana. Pensacola, Mobile and New Orleans are the heaviest u s ers of the Dolores product. This clay n1ay be equally well used for hollow block w are, fireproof ing, and drain tile. It is not sui table, however, for paving brick, sew er pipe, or other vitrified products. It has the following physical propertie s : Physica l Prope rties of Dolores Bric k Company Clay (Lab. No. o-1). Plasticity, judged by feel. . . . . . . . . . . . Excellent. Water of plasticity ................. 22.90% Pore water . . . . . . . . . . . . . . . . . . . . . . . . 1.05% Shrinkage water . . . . . . . . . . . . . . . . . . . 21.85% Volume air shrinkage. . . . . . . . . . . . . . . 21.05% Linear air shrinkage. . . . . . . . . . . . . . . . 7.3 % Modulus of rupture, average ....... . 237.4 pounds per square inch: Slaking test . . . . . . . . . . . . . . . . . . . . . . . 1 hour. Steel hard at cone 15. Fire tests: Temperature. Linear Shr: A bsotption. Porosity. Per Cent. Per Cent. Per Cent. 950C . 0.3 17.31 34.15 . 1050 0 . 3 17.13 33.68 1150 0.3 16.18 1190 0.3 13.51 31.98 1230. 0.7 13.36 31.00 1310 0.7 12.89 30.68 1370 0.7 12.47 29.80 1430 . 1.7 9.03 26 . 84 Color. Light red. Light red. Brick red . Brick red. Brick red. Brick red. Brick red . Brick red. 

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A PRELIMINARY REPORT ON CLAYS OF FLORIDA 157 A common-brick plant was operated at Bluff Springs in the northerp end of the county. This plant u sed surface, sandy clay. FLAGLER COUNTY Flagler County lies on east coast between the St. Johns River valley and the ocean. Its surface exposures show chiefly sands and marls with a few thin local cla ys , with the exception of the western part of the county where some fairly extensive clays of good quality bordering Crescent Lake are found . The western portion of the county is not served by a railroad, but Crescent Lake offers facilities for water transportation by its connecti9n with the St. Johns River. Periodical freight service is maintained by at least one of the lines operating on that river. . . A gray clay exposed in numerous places in the vicinity of Shell Bluff has a thickness of more than eight feet and underlies a considera:ble area in this section of the county. Its overburden consists of le ss than three feet of sat1d and soil. Its plasticity is excellent; it dries without difficulty and its workability is, in general, satisfactory. In most places it is underlain by marl or shell beds. The clay, however, contains numer ous calcareous concretions which render fine grinding and thorough mixing necessary in order to avoid subsequent swelling of the ware due to slaking of the lime. These concret . ions are too small to be successfully screened out without first drying the clay. When properly ground and mixed this clay may be used for com mon brick, drain tile and hollow-block ware. It is not suited, however, for the manufacture of any product where is desired as the ware has a distinctly porous , open texture at 1 5. A samp le of the clay taken fron1 a boring near the office of the Southern Fann Land Con1pany at Shell Bluff has the following physical properties: P!Jysical Properties of Shell Bluff Clay (Lab. No. o-76). Plasticity, judged by feel ........... . Water of plasticity ................ . Pore water ...................... . . Shrinkage water .................. . Linear air shrinkage ............... . Volume air shrinkage .............. . Modulus of rupture, average ....... . Slaking test ...................... . Excellent. 22.30% 1.19% 21.11% 10.5 % 28.3 % 789.9 pounds per square inch. 3 minutes. 

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158 FLORIDA GEOLOGICAL SURVEY-15TH ANNUAL REPORT Fire tests: Temperature. Linear Sl1r. Absorption. Porosity. Color. Per Cent . Per Cent . Per Cent. 950C. 0.5 12.86 31.50 Brick red. 1050 0.5 12.20 30.50 Brick red . 1150 0.5 11.36 29.70 Brick red. 1190 0.5 11.27 29.40 Brick red . 1230 0 . 5 10.75 28.30 Brick red. 1310 1.0 10.15 28.20 Brick red. FRANKLIN COUNTY Franklin County borders the Gulf of Mexico and lies between the Apalachicola and Ocklocknee rivers. The surface exposures consist of sands and marls, but no clays of any comn1ercial importance are lmown . GADSDEN COUNTY Gadsden County l ies in the northwestern part of the State between the Apalachicola and Ocklocknee rivers and the formations exposed are the Chattahoochee, Alum Bluff, and a surface n1antle of Pleistocene or Recent . The Chattahoochee, while primarily a lin1estone, contains some interbedded clays and residua l clays also abound in this formation. The Alum Bluff consists of beds of sand, clay and fuller's earth. In addition to these clays there are some n1ore recent flood-plain clays along the Apalachicola and Ocklocknee rivers. Deposits of sand-clay road material are comtnon in the county and essentially a ll the roads in the . count y are made of this material. Very few of the Chattahoochee formation clays, either the sedimen tary or the residual ones, are of any value for tnanufactured products . In general their working qualities are poor. Most of them are calcareous, h av . e a high shrinkage, warp and crack badly and have poor p l asticity. A sample which may be considered as illustrative of the great n1ass of Chattahoochee clays in the county was taken at an exposure in the road side about two mi l es east of the State I-Iospital near Chattahoochee. This is a grayish-g r een jointed clay of low plasticity, containing a few flint concre . tions .and geodes . It is worked only with difficulty. This clay is not appreciably calcareous. In a burned condition it is suited only for railroad ballast. A few of its physical properties are: 

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A PRELIMINARY REPORT ON CLAYS OF FLORIDA 159 Physical Properties of State Hospital Road Clay (Lab. No. o-79). Plasticity, judged by feel............ Poor. Water of plasticity. . . . . . . . . . . . . . . . . 32.25% Pore water . . . . . . . . . . . . . . . . . . . . . . . . 5.40% Shrinkage water . . . . . . . . . . . . . . . . . . . 29.85% Linear air shrinkage. . . . . . . . . . . . . . . . 17.50% Volume air shrinkage ... :........... 45.75% Steel hard at cone 010. Fire tests: Temperature. Linear Shr. f/ olume Slzr . Per Cent. Per Cent. 2.5 6.7 2.5 7.6 Color. Brick red. Brick red. One of the Chattahoochee limestone residual clays, which is an ex ception to the average condition found in the county, occurs in _ the north east edge of R_.iver Junction where a plant manufacturing common brick was operated in 1907 by Mr. Ed Royston. The product of this plant has been used in the construction of several buildings in River Junction and Chattahoochee. This deposit is located only a few rods from the Atlantic Coast Line and Seaboard Air Line Railway tracks. Four railroads, the Atlantic Coast Line, the Seaboard Air Line, the Louisville and Nash ville, and the Apalachicola Northern, meet at River Junction, thus affording shipping facilities to pojnts in west Florida and southern Georgia and Alabama. The Royston deposit is irregular tn thickness but is as much as fifteen feet in places and underlies a fairly extensive area in a small valley at River Junction. Thi"s is a red-burning clay of tnedium shrinkage and good drying qualities working. It may be used for ordinary structural materials such as co1nn1on brick, hollow-block ware, drain tile, etc. It has the following physical properties: Physical Properties of Royston Clay, Ri<Ver Junction (Lab. No . o-71). Plasticity, judged by feel. . . . . . . . . . . . Excellent . Water of plasticity................. 28.45% Pore water . . . . . . . . . . . . . . . . . . . . . . . . 1.66% Shrinkage water . . . . . . . . . . . . . . . . . . . 26.79% Linear air shrinkage. . . . . . . . . . . . . . . . 11.7 % Volume air shrinkage ............ _... 29.4 % Modulus of rupture, average. . . . . . . . 451.8 pounds per square inch .• Slaking test . . . . . . . . . . . . . . . . . . . . . . . 2 minutes. 

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160 FLORIDA GEOLOGICAL SURVEY-15TH ANNUAL REPORT Fire tests: Temperature. 950C. 1050 1150 1190 1230 1310 Linear S!Jr. Per Cent . 0.2 0.3 0.8 1.3 . 1.8 2.8 Absorption. Per Cent. 11.02 11.50 11.11 10.22 9.73 9.60 Porosity. Per Cent. 29.10 28.20 27.10 26.80 25.10 24.75 Color. Brick red. Brick red. Gray. Gray. Gray. Gray. The Alum Bluff clays were formerl y worked in a number of places in Gadsde . n Coun . ty. One plant was operated at Hinson about sixty-five years ago. Plants have also been located near Mount Pleasant, Gretna, Quincy, and Chattahoochee. The plant at Q : uincy worked one of the clays overlying the fuller's earth. This clay is now removed as overburden in mining the fuller's earth and . could therefore be used as a by-product. It has medium shrinkage, good working qualities and is suitable for common brick, hollow blocks and drain tile . A vitrified product cannot satisfactorily be made from it, however, as it still has a porous; open texture at cone 15. It has the following physical properties: Physical Properties of Floridin Overburden Clay, Quincy (Lab. No. o-38). Plasticity, judged by feel ........... . Water of plasticity ................ . Pore water ....................... . Shrinkage water .................. . Linear air shrinkage ............... . Volume air shrinkage ............. . . Modulus of rupture, average ....... . Slaking test ...................... . Steel hard at cone 5 . Fire tests: !emperature. LinearShr. Absorption. Per Cent. Per Cent. 950C. 1.2 11.40 1050 1.7 11.10 1150 1.8 . 11.10 1190 2.2 10 \ 50 1230 2.8 10.50 1310 3.7 8.33 Excellent. 25.65% 0.50% 25.15% . 12.20 36.82% 315 . 7 pounds per square inch . 2 minutes . Porosity. Color. Per Cent. 27.85 Brick red. 27.20 27.20 27.10 27.10 Underlying the northeast part of the town of C . hattahoochee and also forming the surface materials at the headquarters of the State Hospital is a deep red, very sandy clay. It is valueless for fired products, but is suitable for sand:-clay road metal. As an illustration of this type of clay ihe following physical properties are given: 

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A PRELIMINARY REPORT ON CLAYS OF FLORIDA Physical Properties of State Hospital Red Sandy Cia! (Lab. No. o-37). Plasticity, judged by feel .......... . . Water of plasticity ........ .... .... . Pore water ....................... . Shrinkage water .................. . Linear air shrinkage ............... . Volume air shrinkage .............. . Modulus of rupture, average ....... . Slaking test ........... _. .......... . Fire tests: Temperature. 950C. 1050 1150 Linear Shr. Per Cent. 0.6 0 .6 1.4 Absorption. Per Cent. 22.37 18.40 17.45 Fair. 21.40% 0 .10% 21.30% 6.40% 17.90% 84.5 pounds per square inch. 36 hours. Porosity. Per Cent. 36.70 36 .50 36.50 Color . Brick red. 161 A clay. exposed on the A. J. Key Plantation, _ about three miles southeast of Quincy on the Seaboard Air Line Railway, contained numerous limonitic concretion s. The plasticity and drying qualities arc good, but the transverse .strength is very low. This clay is of no practical value for the manufacture of burned products. Its physical propertie s are: Physical Properties of Key Plantation Clay (Lab. No. 0-41). Plasticity, judged by feel.. .......... Excellent. Water of plasticity............... . . 24.75% Porewater . . . . . . . . . . . . . . . . . . . . . . . . 0.27% Shrinkage water . . . . . . . . . . . . . . . . . . . 24.48% Linear air shrinkage................ 5.70% Volume air shrinkage............... 15.75 % Modulus of rupture, average .... ... : 92.5 pounds per square inch. Slaking test . . . . . . . . . . . . . . . . . . . . . . . 24 hours. Overfires at cone 5. Fire tests: Temperature. Linear Slzr. Absorption. Po r osity. Color. Per Cent. Per Cent. Per Cent. 950C. 0 . 3 26.60 45.80 Brick red. 1050 0.8 24.48 43. 10 Brick red. 1150 2.3 23.55 43.60 Brick red. 1190 3.3 16.70 37.10 Brick red. By far best clays in the county for burned products are the flood-plain clays along the Apalachicola and Ocklocknee rivers. One such deposit is located on the State Hospital Farn1, one mile north west of Chattahoochee, in a _ field joining the Apalachicola R1ver and the boundary . The thickness of this deposit not definitely known, but it is more than fiv e or six feet. It i s known to underlie an area of sixty or eighty acres in Georgia and Florida. 

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162 FLORIDA GEOLOGICAL SURVEY-I 5TH ANNUAL REP-ORT This clay may be used to make an excellent grade of common build ing brick and similar structural materials. Rail trans portation is not nearer than about three miles, but the Apalachicola offers water transportation to points down that river and up the Flint and Chatta hoochee Rivers in Georgia and Alabatna. This clay has the following physical properties : Physica l Properties of State Hospital Rive r Field (Lab. No. o -8). Plasticity, judged by feel ........... . Water of plasticity ......... . . . . ... . Pore water .... ................... . Shrinkage water ........ .......... . Linear air shrinkage .... ........... . Exce ll ent. 26.50% 0.94% 25.56% 8.1 % 23.6 % Volume air shrinkage. , . ........... . Modulus of rupture, average ....... . 301.1 pounds per square . inch. Slaking test ...................... . 36 hours. Steel hard at cone 9. Fire tests: Temperature. Linear Shr. Absorption. Porosity. Colo r . Per Cent. Per Cent. Per Cent. 950 C . 0.9 17.9 5 39.02 Brick r e d . 1050 1.1 20.50 39.40 Brick red. 1150 1.9 1 6.45 39.40 Brick red. 1190 4.4 13.15 38.50 Brick red. 1230 4.9 12.70 31.20 Brick red. 1 310 4.9 8.35 31.60 Brick red. 1370 5 .4 3.29 25.50 Brick red. 1430 7.9 14.90 Brick red. The Ocklocknee Brick Company, located on the Seaboard Air Line Railway at Lawrence, uses a flood-plain clay. The deposit is five feet thick and is overlain by six inches of soil. The clay has good plastic ity and bonding strength and present s no drying difficulties. It is now used in the manufacture of common brick. An excellent grade of com mon brick, hollow-block ware, and drain tile n1ay be n1ade from it. A serjes of compression tests made on the Ocklocknee Brick Company's product by the Birmingham branch of the Pittshurgh Testing Laboratory were as follows : Weight pounds. No. 1--4.1 No. 2--4.1 No. 3--4.2 Average Comp r ession Tests on Ocklocknee Brick. HARD BRICK. Dim enArea, square Load, szons. inches. pounds. 3 . 6x7.8 28.08 78,900 3.7x7.7 28.49 83,600 3 . 7x7.8 28.86 88,500 Unit load, pounds per square inch. 2,810 2,9'35 3,067 2,937 

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A PRELIMINARY REPORT ON CLAYS OF FLORIDA 163 Weight pounds. No. 1-4.3 No. 2-4.3 No . 3-4.2 Average Weight pounds. No. 1-4.1 No. 2-4.0 No . 3-4.0 Dim en-. szons. 3 . 7x7 . 6 3.6x7.7 3.6x7.6 . . szons. 3.7x7.8 3.7x7.7 3.6x7.6 MEDIUM BRICK . Area_, square inches. 28. 1 2 27 . 72 27 .36 SOFI' BRICK. Area, square inches . 28. 86 28.4 9 27.36 Load pounds. 73,560 73,190 7 . 5,140 Unit load_, pounds per square inch 2,617 2,640 2,746 2,668 Load Unit load, pounds pounds. per square inch 106 ,200 p l us 3,680 plus 99,890 3,506 106,200 plus 3,882 p l us Average . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3,689 plus The Ocklocknee clay has the following physica l properties : Physical Properties of the Ocklocknee Clay (Lab. No. 0-30). P l asticity, judged by feel . . . . . . . • . . . . Excellent. Water of plasticity................. 26.00% Pore water . . . . . . . . . . . . . . . . . . . . . . . . 0 .52% Shrinkage water . . . . . . . . . . . . . . . . . . . 25.48% Linear air shrinkage. . . . . . . . . . . . . . . . 12.2 % Volume air shrinkage.............. . 33.2 % Modulus of rupture, average........ 988 . 0 pounds per square inch. S laking test . . . . . . . . . . . . . . . . . . . . . . . 2 days. S'teel hard at cone 010. Fire tests: Temperature. Linear Shr. Absorption. Porosity. Color. 950 C. 1050 1150 1190 1230 1310 1370 1 430 Per Cen t . Per Cent. Per Cent . 0.2 13.10 28.40 Reddish 0.7 14.22 29.00 Reddish 0.8 10.50 25.50 Reddish 0.3 9.75 24.00 Re ,ddish 0.3 9 .60 23.20 Reddis h 3.8 9.05 22.75 Reddish 4.3 9 .55 20.30 Reddish 4 . 8 8.42 18.75 Reddish FIG. 23.-General View, Ocklocknee Brick Co., Lawrence, Gadsden County. . brown. brown. brow n . brown. brown. brown. brown. brown. 

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164 FLORIDA GEOLOGICAL SURVEY-15TH ANNUAL REPORT The Tallaha ssee Pressed Brick Company, Havana, located farther up the Ocklockne e River, also utilizes a flood-plain clay having properties very similar to the clay previou s l y de s cribed. Tliis plant is located on the Georgia, Florida and A labama Railroaq. The deposit is about five feet thick, overlain by about six inches of soil, and has been proven on about sixty acres. It probabl)\ underlies a more extensive area. This clay has excellent working A good grade of com mon building . brick, fireproofing, hollow blocks, or drain tile may be made from it. Its physical properties are: Physical Properties . of the Tallahassee Pressed Brick Company Clay (Lab. No. o-17). Plasticity , judged by feel ........... . Water of plasticity ............ .. .. . Linear air shrinkage ............... . Volume air shrinkage .............. . Modulus of rupture, average ....... . Slaking test .......•............... Steel hard at cone 010 . Fire tests: Temperature. Linear Shr. Absorption. Per Cent . Per Cent. 950C. 0.3 17.32 1050 0.3 16.80 1150 0.7 14.20 1190 0.7 11.4 2 1230 1.2 11.05 1310 1.8 . 10.90 1370 2.2 10.18 1430 2.2 9.30 ' Excellent. 25.65% 10.3 % 27.8 % 498.4 pounds per square inch. 48 hours. Porosity. Color. Per Cent. 33.00 Brick red. 32.45 Brick Red. 30.25 Brick Red. 25.50 Brick Red . 29.20 Brick Red. 23.75 Brick red. 20.20 Brown. 14.20 Brown. The two plants located on the Ocklocknee River supply a demand for brick throughout northwestern Florida and southern Georgia. GLADES COUNTY Glades County borders Okeechobee on the west and is under lain chiefly by sands and marls in which exposures are rare. No clays of importance are known . HAMILTON COUNTY Hamilton County is loce1:ted in north Florida between the Suwannee and Withlacoochee rivers. The surface materials are chiefly Chattahoochee, Alum Bluff and Recent formations, in which surface, sandy clays, in places containing some gravel, are common. 

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A PRELIMINARY REPORT ON CLAYS OF FLORIDA 165 At the bridge across the Suwannee River at White Springs an eight foot bed of a green-colored, plastic, jointed clay, overlain by six feet of soil, is exposed. This clay has a high air shrinkage and warps and cracks badly in drying and burning. It therefore is of no value in the n1anufacture of burned clay products. An exposure of a soft, white shale or partially consolidated clay occurs on the west bank of the Suwannee River about five miles northeast of White Springs. Only one . exposure of this clay was seen in thi _ s vicinity, but it probably underlies a considerable on both sides of the river. The deposit is overlain by a sand ranging from six to ten feet in thickness . A twenty-two-foot of day is exposed above the river level. Its depth below the river is not known. This clay has excellent plasticity and working qualities and dries without difficulty . . Its high air and fire shrinkage are detrimental and this, in connection with a slight tendency to warp in firing, rende _rs it useless for burned products. The clay vitrifies at cone 3 and becomes distinctly porous at cone 5. Its physical properties are: Physical Properties of White Springs White Shale (Lab. No. 0-3). Plasticity; judged by feel. .......... . Water of plasticity . ........ ....... . Pore water : ...... ; ......... . .... . . Shrinkage water . ...... ........... . Linear air shrinkage ............... . Volume air shrinkage ............ ... _ Modulus of rupture, average ...•.... Slaking test ...................... . Steel hard at cone 010. Fire tests: Temperature . 950C. 1050 1150 1190 1230 Linear Shr. Per Cent. 8.2 5.7 15.7 16.7 14.7 Absorption. Per Cent. 32.20 30.51 17.02 1.33 0.78 Excellent. 52.50% 12.80% 39.70% 14.3 % 42.8 % 470 . 8 pounds per square inch. 24 hours. Porosity. Per Cent. 52.63 46.02 31.82 5.72 2.97 Color. Cream. Cream. Light yellow. Light yellow. Light yeiiow. HARDEE COUNTY Hardee County situated in south Florida and is underlain by the Bone Valley and Caloosahatchee formations. _ The Bartow Clay is found extensively throughout the central and western parts of the . county. (For discussion on the Bartow Clay see Polk County, page 195.) A coarse, reddish to brownish, sandy clay is exposed near Bowling Green, Zolfo 

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166 GEOLOGICAL SURVEY-15TH ANNUAL REPOR'l' and Wauchula. This n1aterial is desirable for sand-clay road metal. No clays suited for burned products are known in the county. HERNANDO COUNTY Hernando County is situated on the Gulf coast in west-central Florida and is underlain by the Ocala and Tampa formations. Tampa formation occupies the southeastern part of the county and sev eral outliers scattered northward throughout the region of the Ocala formation. Brooksville, the county seat, is located in the center of one of these having a radius of about six miles. Residual clays are of common in both the Ocala and Tampa limestones, but sedimentary clays occur ori1y in the Tampa formation. The Ocala residual clays are usually sandy, contain numerous flint concretions and the deposits are very irregular in thickness and extent. Pockets of such clay are frequently encountered in mining the rock phosphate which occurs extensively in this region. These clay pockets are of insufficient size to warrant the separation of the clay from the other materials. The Tampa formation clays are worked at Brooksville and are found at numerous other localities in that vicinity. Few of them are de sirable for burned products as their working qualities are rather poor. They are subject to excessive cracking during drying and burning which would result in severe losses during the process of manufacture. The transverse strength is relatively low in all of them. The Morris and Blumer Brick Company, located about one mile south of Brooksville, works one of these Tampa formation residual clays. The deposit consists of two parts; an upper two feet, which is dark-brown in color and somewhat sandy, and a lower member, which is very light in color and averages about eight feet in thickness . The deposit is underlain by the Tampa limestone and is separated from it by an irregular contact. Flint and limestone concretions occur in the clay. The contact between the two members of this deposit is fairly distinct and probably represents a former water table. This deposit underlies an extensive area south and west of Brooksville . At this plant the dark upper clay and the lower white one are mixed in equal proportions. The sand in the upper clay somewhat reduces the shrinkage of the mixture. These clays can be dried only with difficulty. 

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A PRELIMINARY REPORT ON CLAYS OF FLORIDA 167 The green brick are stacked in air-drying sheds where they are protected from wind and direct sunlight. They are first covered with wet burlap and the ground underneath the racks is flooded with water to prevent rapid drying. Eight weeks are required to dry the ware in this manner without heavy l os s es f rom ct:acking. Careful firing with very gradual increases in temperature are also nece ssary to avoid further crack ing. A common building-brick is tnade at this plant. Ftc. 24.-Setting a kiln. Morris and Blumer Brick Company, Brooksville, Hernando County . The plant i s l oca te d o n the Tampa Iorthern Railroad, which renders Tampa and St. Pete r sburg and surrounding points available as a market. The upper dark, sandy cray has the following physical properties: 

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168 FLORIDA GEOLOGICAL SURVEY-I 5TH ANNUAL REPORT Physical Properties of Morris and Blumer; Brick Company Upper Sandy Clay (Lab. No. o-2]}. Plasticity, judged by feel. . . . . . . . . . . . Excellent. Water of plasticity................. 24.95% Pore water . . . . . . . . . . . . . . . . . . . . . . . . . 0.51% Shrinkage water . . . . . . . . . . . . . . . . . . . 24.38% Linear air shrinkage . . :.. . . . . . . . . . . . 12.7 % Volume air shrinkage............... 31.1 % Modulus of rupture, average... ..... 345.4 pounds per square inch . Slaking test . . . . . . . . . . . . . . . . . . . . . . . 5 minutes. Overfires at cone 9. Fire tests: Temperature. Linear SIJr. Absorption. . Porosity. Color. Per Cent. Per C-ent. Per Cent. 950C. 0.7 11.82 23.95 Buff. 1050 0.3 12.38 26.75 Buff. 1150 0.3 11.68 26.45 B ' uff. 1190 0.3 11.40 25.50 Buff. 1230 0.5 11.40 26.45 Buff. 1310 2.3 11.80 27.75 Buff. The lower light-colored clay has the following physical properties: Physical Properties of Morris and Blumer Brick Company Lower White Clay (Lab. No. o-24). Plasticity, judged by feel............ Excellent. Water of plasticity................. 36.40% Pore water . . . . . . . . . . . . . . . . . . . . . . . . 0.88% Shrinkage water . . . . . . . . . . . . . . . . . . . 35.52% Linear air shrinkage. . . . . . . . . . . . . . . . . 8.90% Volume air shrinkage........ .... ... 22.05% Modulus of rupture, average........ 114.0 pounds per square inch. Slaking test . . . . . . . . . . . . . . . . . . . . . . . 3 minutes. Steel hard at cone 010. Fire tests: Temperature. #"Linear Shr. Absorption. Porosity. Color. Per Cent. Per Cent. Per Cent. . 950C. 11.4 4.58 12.15 Salmon. 1050 13.6 4.50 10.45 Gray. 1150 13.6 Gray. 1190 13.1 3.53 8.95 Gray. 1290 13.1 2.58 6.65 Gray. 1310 12.1 1370 16.1 . A sin1ilar clay is exposed a few rods south of the Tampa Northern station. It may likewise be for a common brick, but it also requires very careful drying and burning to avoid excessive crack mg. Its physical properties are: 

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A PRELIMINARY REPORT ON CLAYS OF FLORIDA Physical Properties of Brooksville Tampa Northern Clay (Lab. No. o-21). Plasticity, judged by feel ........... . Water of plasticity ................ . Linear air shrinkage ............... . Volume air shrinkage .............. . Modulus of rupture, average ....... . Slaking test ..... ................. . Steel hard at cone 010. Overfires at cone . 9. Fire tests: Temperature. Linear Shr. Absorption. Per Cent. Per Cent. 950C. 0.0 7.60 1050 2.8 7.08 1150 . 3.8 6.88 1190 5.8 6 . 42 1230 3.8 5.82 Excellent. 34.50% 15.2 % 41.2 % 147.0 pounds per square inch. 3 minutes. Porosity. Color . Per Cent. 18.50 Salmon. 18.30 Brown. 16.20 Gray. 15.70 Gray. 10 .10 Gray. 169 A clay is exposed in the northeastern edge of Brooksville and vicin ity which is unfitted for any kind of burned product. Its plasticity is very poor and its shrinkage is high. This clay warps badly, but is compara tively free from cracking . Its physical properties, which are given for the purpose of illustration, are: Physical Properties of Brooksville Clay (Lab. No. o-56). Plasticity, judged by feel ........... . Water of plasticity ................ . Pore water ....................... . Shrinkage water .................. . Linear air shrinkage ............... Volume air shrinkage ......... : .... . Modulus of rupture, average ....... . Slaking test ...................... . Steel hard at cone 010. Fire tests: Temperature. Linear Shr. Absorption. Per Cent. Per Cent. 950C. 3.2 6.46 1050 4.2 6.02 1150 6.7 6.61 1190 7.0 5.49 Poor. 38.45% 4 .90% 33.55% 18. 8 % 35.8 % 218. 0 pounds per square inch. 5 minutes. Porosity. Per Cent. 17.20 Salmon. 16.30 Salmon. 16.60 Gray. 13.40 Gray. A brownish-gray, slightly sandy clay occurs in the Annuttalaga Hammock about one-half mile north of Brooksville and extends northward for about two tniles. The thickness of the deposits _ is not known, but is as tnuch as eight feet in places. The clay is suitable for a soft, porous common building brick of fair quality. Its physical prop erties are: 

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170 FLORIDA GEOLOGICAL SURVEY-15TH ANNUAL REPORT Physical PropertieJ of Brooksville Hammock Clay (Lab. No. 0-59). Plasticity, judged by feel .......... . Water of plasticity ................ . Pore water ..................... . . . Shrinkage water .................. . Linear air shrinkage .... ! ••••••••••• Volume air shrinkage ...... . . ...... . Modulus of rupture, average . ...... . Slaking test ......... ............. . Fire tests : Temperature. LinearShr. Absorption. Per Cent. Per Cent. 950C. o.47 16.16 1050 0.4 16.64 1150 1.6 15.80 1190 2.4 16.00 1230 2.9 15.49 Excellent. 27.40% 1.49% 25.93% 12.1 % 28.8% 215.3 pounds per square inch. 3 minutes. Porosity. Color. Per Cent. 34.80 Brick red. 34.40 Brick red. 33.50 Brick red. 27.75 Brick red. 23.75 Brick.red. HIGHLANDS COUNTY Highlands County l ies in the south-central part of the peninsula just northwest of Lake Okeechobee. The Alum Bluff formation under lies the central part of the county from Lake Childs northwestward and contains abundant coarse, red, sandy day very suitable for sandclay road material. The remainder of the county is underlain by sand and marls. No clays suitable for burned products are known. HILLSBOROUGH COUNTY Hillsborough County lies on the western side of the peninsula at the head of Tampa Bay . It is underlain by the Tampa, Alum Bluff and Bone Valley formations. The Bone Valley Gravel carries the Bartow clay which is founp in numerous localitie s from Plant City southward to the Manatee River. (For a description of the Bartow Clay see Polk County, page 195.) The Alum Bluff formation contains some phosphatic and sandy clays, but none having any usefulness for burned products. The Tampa formation consi?ts of two distinct strata of plastic clays separated by a lime stone. The upper clay is exposed in numerous localities, while the lower one has very few, if any, natural exposures and is found chiefly in excavations and wel15. Residual clays from the Tampa lime stone are of common -occurrence. 

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A PRELIMINARY REPORT ON CLAYS OF FLORIDA 171 The upper Tampa clay is exposed in several places along the Hills borough River and has formerly been worked at Taf!I-pa. Both the Tampa Northern Railroad and the Atlantic Coast Line Railroad cross exposures of this clay. The Tampa Brick Company's plant, now abandoned, was located about five miles northeast of the city on the Hillsborough River . The de posit consists of about ten feet of a l ightgreen plastic clay containing numerous cherty concretions. A two-foot ov erburden of loose surface sand and soil overlies the clay . This is a grayish, buff-burning clay which is still distinctly porous at cone 15, hence is not suited for any product where vitrification is essential. It may, however, be used for comtnon building-brick and hollow-block ware. Its physical properties are: Physical Properties of Tampa Brick Company Clay (Lab. No. 0-34) . Plasticity, judged by feel ........... . Excellent. Water of plasticity ................ . Pore water ................ ....... . Shrinkage water .................. . Linear air shrinkage ............... . Volume air shrinkage ............... . Modulus of rupture, average ....... . Slaking test : ..................... . Fire tests: Temperature. Linear Shr. Absorption. ' Per Cent. Per Cent. 950C. 0.3 16.75 1050 0.3 16.20 • 1150 0.2 14.18 1190 2.2 14.20 1230 2.2 13.25 1310 13.20 32.45% 1.05% 31.40% 12.80% 35.85% 598. 2 pounds per square inch. 5 minutes. Porosity. Color. Per Cent. 31.50 Buff : 31.10 Buff . 29.75 Buff. 27.80 Buff. 27.70 Buff. 26.60 Buff . The Temple Terrace Tract, located about six miles Llortheast of Tampa on the Hill s borou g h River, is underlain by a yellowish and red dish, sandy clay which is suited only for sand-clay road material. The southern edge of the tract is underlain b y the Tampa forn1ation clay which has the s ame properties as the Tampa Brick Company clay described in the foregoing paragraph. The property of Dr. W. P. Chamberlain, two miles north of .Sulphur Springs, is underlain by several thin variable clay strata interbedded with sand. The clay is of insufficient quantity and at too great depth to 

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172 FLORIDA GEOLOGICAL SURVEY-15TH ANNUAL REPORT be of any cotnmerciat" value. One boring about one-quarter mile north west of the house indicated the following section: Section of Strata on tlu Dr. W. P. Chamberlain Pr,operty, near Sulphur Springs. Sand, gray .................................... ....... . Sand, white ................... ...... ................. . Clay, gray, very plastic ............................... . Sand, w bite ......................................... . . Clay, red, plastic ..................................... . S ' and, white .......................................... . Feet. Inches. 2 12 2 ? 2 2 2 Another boring only about ten rods to the northeast of the foregoing one showed the gray, plastic clay to have a thickness of one and one half feet. Pockets of a buff, plastic clay, residual from the Tampa limestone, are of common occurrence in the western edge of Tatnpa and beyond the city limits. These are exceedingly irregular in and extent and are of insufficient size to warrant exploitation. HOLMES COUNTY Holmes County lies in northwest Florida adjoining the Florida Alabama boundary and is underlain by the Ocala, and Alum Bluff formations . Sandy surface clays are of common occurrence but none are known that are desirable for burned products. JACKSON COUNTY Jackson County lies in west Florida just west of the Apalachicola Riyer. It is underlain by the Ocala, Marianna, Chattahoochee, Alun1 Bluff, and Pleistocene formations. Residual Ocala, Marianna and Chat tahoochee clays are found, but few are of commercial importance. The Alum Bluff formation consists essentially of sands and marls. S01ne Pleistocene flood-plain clays occur along the Apalachicola River. A deposit of clay, probably Pleistocene, occurs on the property of the Florida Industrial School for Boys, three miles southwest of Marian na, and is now being worked for. common brick. This is a red and gray clay from eight to twelve feet thick overlain by a brown, sandy clay fron1 one to two feet in thickness. Marianna is the nearest shipping point, but most of the output fron1 this plant is used on the farm and the remainder is sold locally. 

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A PRELIMINARY REPORT ON CLAYS OF FLORIDA 173 The plant i s sm all and h as only one kiln which h as a 110,000 capaci t y . A ll the work is done by boys ranging in age from eight t o e i ghteen years. The clay ha s excellent pla s ticit y. Its lin ea r fire s hrinkage incr eas e s from 3.1 per cent at cone 010 to 10 .6 per cent a t co ne 5. Its porosity and ab so rption percentages a r e low at cone 1 and remain so un til after cone 9 is passed. Thi s clay s hould be u se d on l y for con1mon structural materi a l s as common and face brick, firepro o fing, hollow-block wa re, drain tile and simila r products and sho uld be burned at about cone 0 10. Its physi cal p rop erties are: P!JyJical PropertieJ of Florida lndu Jtrial Sc!Jool Clay (Lab. No. o-28) . Plasticity, judge d b y feel .......... . Water of plasticity .............. . . . P o r e water ............. .......... . Shrinkage water .................. . Linear air shrinkage ............... . Volume air shrinkage .... . ......... . Modulus of rupture, average ....... . Slaking test ...................... . Ste e l hard at cone 010. Overfires at cone 12. Fire tests : Temperatur e. Linear Shr. Per C e nt. 950 C. 3 .1 1050 10.6 1150 10.6 1190 1 2.6 1230 12 . 6 1310 13.6 A bJorption. P er Cent. 11.95 8.05 2.10 1.70 1.67 1 .5 0 Excellent. 36.65% 0 .46% 36.19% 14.40% 38.10% 421.2 pounds per square inch. 5 minutes. P oroJity. Color . Per Cent. 26.00 Brick red. 20.75 Brick red. 8.60 Brick r e d . 7.50 Brick red. 5.80 Brick red. 6.10 Brick red. JEFFERSON COUNTY Jefferson County lies in north Florida and extends from the north ern bounda r y of the State t o the Gulf of Mexico. It is underlain by the Alun1 Bl uff formatio n in the north ern part of the county and the Chat tahoochee fonnation in the so uthern part. A h eavy mantle of red, coarse, sandy clay covers most of the county. Severa l brick plants h ave forme rl y bee n opera ted in the county. Three of these, lo cated near Monti cello, have worked a sandy, joi nted, surface clay. Another small p l an t worked a red surface clay on the Bis h op Homestead, four miles south of A ucilla. Clays from ea c h of these localitie s may be used for common brick. The Bisho p clay is too far from t ransporta ti o n to be o f commerc ia l i mpo rtance. 

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1 '('4 FLORIDA GEOLOGICAL SURVEY-I 5TH ANNUAL REPORT In a series of tests made by the United States Bureau of Standards in 1914 a clay fron1 near Thotnas City was included. Its qualities indi cate that it n1ay be used for a con1mon building-brick. Its r>hysical properties are :1 Physical Properties of T'IJoma.r City Clay (Bureau of Standards Sample No. 21). Plasticity. . . . . . . . . . . . . . . . . . . . . . . . . . Good. Water of plasticity.............. . . . 28.9% Linear air shrinkage.............. . . 6.0% Fire tests: Temperature. 950C. 1020 1050 1080 1110 1140 1170 1200 1230 1260 1290 1320 Linear SIJr. Per Cent. 0.22 1.09 0.55 0.49 Porosity. Per Cent. 35. 6 . 34.0 32.2 33.4 33.8 33.6 33.6 33. 7 32.8 34.4 33.7 33.5 LAF A VETTE COUNTY Color. Buff. Buff. Buff. Buff. Buff. Buff. Buff. Buff. Buff. Buff. Buff. Buff. Lafayette County lies in .the northwestern part of the peninsula and is underlaid by the Ocala and Chattahoochee formations. Both of these contain clays to some extent but none that tnay be considered of com mercial importance. LAKE COUNTY Lake County lies in the central part of the peninsula in the heart of the Lake Region. Its surface formations are essentially all sand-clays in which there is a high percentage of coarse, sharp, angular sand and some gravel with a good, reddish, clay bond. This material is very desirable for sand-clay road material, but is not adapted to other uses. Extensive deposits of sedimentary kaolins also occur in Lake Coun ty and are discussed in detail in a subsequent chapter. (Chapter IX.) Numerous lacustrine deposits also occur in Lake County. These are usually of lin1ited areal extent and relatively thin. One of these occurs on the property of B. H . . N uckoll s near Umatilla (Sec. 1, Twp. 18 S., R. 26 E.). This is a blue clay with a bright-red mot-lSellards, E. H., Report of Clay Tests for Paving Brick, Florida Geological Survey Press Bulletin No. 7, 1915. 

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A PRF. f.I M INAR Y REPOR'l' ON CLAYS O F FLORIDA Ftc. 25. C i ay pit, Keys tone Brick Co., Whitney , L a k e County . Frc. 26.-View s h owing kiln seal e d read y f o r fir in g. K eystone Brick Co., Whitney, Lake County. 175 

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176 . FLORIDA GEOLOGICAL SURVEY-I 5TH ANNUAL REPORT tling, having excellent plasticity but a high air shrinkage. It occur s in a bed two and onehalf fe et thick overlain by s i x feet of sa n d. overburden is too heavy for a clay of that thicknes s to be of commercia _ ! importance. The Keystone Brick Company at Whitney works a lacustrine de posit ranging from sev en to twelve feet in thickness and overlain by about eighteen inche s of sand. The clay is also underlain by sand. T wo pits about sixty yards apart have been opened. The in one of these is a little more sandy than in the other. A good grade of common brick is made which is shipped to market s throughout peninsular Florida. Tatnpa and St. Petersburg use the greater.part of the output. This plant is located on a branch of the Sea board Air Line Railway. The I ( e yston e brick, w hile n(?t particularly a semi-refractory product, is widely used in South Florida for fire-box lining under boilers. This clay retains a soft, porous texture at cone 15 and may be used only for com mon building-brick. Its physical properties are: Physical Properties of Keystone Brick Company Clay (Lab. No. o-54). Plasticity, judged by feel .....•..... Water of plasticity ................ . Pore water .................. ..... . Shrinkage water .................. . Linear air shrinkage ............... . Volume air shrinkage ...... ........ . Modulus of rupture, average ....... . Slaking test ..... ................. . Fire tests= E xcellent. 23.90% 1.58% 22.40% 10.9 % 32.3 % 491.3 pounds per square inch. 5 minutes. Temperature. Linear Shr. Absorption. Porosity. Color. Per Cent . Per Cent. PerCent. 950C. 0.6 19.84 33.40 Brick . red. 1050 1.1 11.49 30.20 Brick red. 1150 1.1 9.43 26.90 Brick red. 1190 1.6 9.78 26.50 Brick red. 1230 2.1 9.69 24.20 Brick red. 1310 2.6 8.40 23 .50 Brick red. Another brick plant was formerly operated near Whitney by the Whitney Brick Company. The deposit . was a sandy lacustrine clay, from which a red common brick was made. LEE COUNTY Lee County lies between Lake Okeechobee and the Gulf of Mexico and is underlain by sands, marls and limestones of Pleistocene age. No clays of . importance are known. 

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A PRELIMI. NARY REPORT ON CLAYS OF FLORIDA 177 LEON COUNTY Leon County is located in north Florida east the Ocklocknee River. The Chattahoochee, Alum Bluff, Choctawhatchee and Pleistocene formations are expos .ed at the surface. A surface mantle of a jointed sandy clay, probably Pleistocene, covers the entire county. Flood-plain clays occur at some points along the Ocklocknee River C}.nd lacustrine clays are also found in several places. . Many years ago, before there were railroads to bring better n1aterial from other localities, bricks were made from sandy red clay just north of Tallahassee, and the remains of the yards can still be seen. The surface mantle clays occupying the northwestern half of the county and roughly co-extensive with the Alum Bluff formation contain mu.c.h coarse sand and some This material is well suited for sand-clay road material. The surface material in the southeastern part of the county and essentially co-extensive . with the Chattahoochee formation contains a high percentage of clay. An. exposure of this clay occurs in a road-clay pit about six miles south of ':fallahassee on the Woodville road and just north of the Wakulla Hammock. The thickt:Jess of this deposit is not known, but more than five feet are exposed. It is overlain by about eighteen inches of surface sand and soil. This clay may be . used for a fair grade of common brick, but as it retains a porous texture even at cone 16, it cannot be used for a vitrified product. It has the following physical properties : PIJysical Properties of the Woodville Road Clay (Lab. No. O-S). Plasticity, judged by feel... . . . . . . . . Fair. Water of plasticity................. 31.40% Pore water .......... . . . . . . . . . . . . 1.33% Shrinkage water ......... . . . . . . . . . . 30.07% Linear air shrinkage. . . . • . . . . . . . . . . . 11.3 % Volume air shrinkage........ . ...... 29.8 % Modulus of rupture, average........ 225.6 pound s per square inch. SJaking test . . . . . . . . . . . . . . . . . . . . . . . 24 hours. Fire tests: T empetature. Linear Shr. Absorption. Porosity . Color. Per Cent. Per Cent. Per Cent. 950C. 1.2 17.30 35.00 Buff. 1050 1.7 18.20 35.00 Buff. 1150 4.7 14.00 27 .80 Buff. 1190 5.7 13.20 27.80 Buff. 1230 6 .2 11.40 25.90 Gray. 1310 6.7 10.00 19.30 Gray. 1370 6.7 9.20 19.90 Gray. 1430 7 .7 8.50 18 .60 

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178 FLORIDA GEOLOGICA _ L SURVEY-I 5TH ANNUAL REPORT A clay exposed in several cuts along the St. Augustine Road in the region about Chaires and Capitola underlies an area in thi s vicinity, but is not suited for the tnanufacture <?f burned products. A sample taken from a pit one-half mile west of Capitola, between the Sea board Air Line Railway and the highway, has the following physical properties, which are given as illustrative of the clays of this general . . region: Pl1ysical Properties of the Capitola Clay (Lab. No. o-16). Plasticity, judged by feel. . . . . . . . . . . Fair. Water of plasticity................. 28.90% Linear air shrinkage :............... 7 . 4 % Volume air shrinkage............... 18.6 % . . . Modulus of rupture, average. . . . . . . . 128.3 pounds per square iQch. Slaking test . . . . . . . . . . . . . . . . . . . . . . . 2 hours. . Fire tests: Temperature. Linear Shr. Absorption. . Porosity . Color. Per Cent. Per Cent. Per Cent. 950C. 0.1 18.30 36.20 Brick red. 1050 0.9 18.90 36.60 Brick red. 1150 1.4 18.58 36.10 Brick red. 1190 1.4 17.65 34.50 Brick red. 1230 1.9 15.30 32.50 Brick red. A lacustrine deposit occurs on the property of C. W. Burney, onehalf mile south of adjoining the Atlantic Coast Line Rail road . It is grayish-brown in color, contains some sand and is overlain by about three feet of soil. The clay is more than five feet in thickness and underlies approximately ten acres. This clay burns to a light pinkish-white at cones 010 and 05. It may be used for a fair grade of common brick, but on account of a highly-porous texture which it retains at cone 16 a vitrified product would be impracticable. It has the fol lowing physical properties: Physical Properties of C. W. Burney Clay, Miccosukee (Lab. No. o-10). Plasticity, judged by feel . . . . . . . . . . . ExcelleQt. Water of plasticity.............. ... 23.50% Pore water . . . . . . . . . . . . . . . . . . . . . . . . . . 0.64% Shrinkage water . . . . . . . . . . . . . . . . . . 22.86% Linear air shrinkage. . . . . . . . . . . . . . . 7.6 % Volume air shrinkage..... .......... 20.8 % of rupture, average........ 129.2 pounds per square inch. Slaking test . . . . . . . . . . . . . . . . . . . . . . . 24 hours. Fire tests : Temperature. Linear Shr. Absorption. Porosity. Color. Per Cent. Per Cent . Per Cent. 950C. 1.4 23.62 38.70 Pink. 1050 1.4 21.00 38.60 Pink. 1150 1.4 19.00 36.20 Brown. 1190 1.4 15.95 33.75 Pink. 1230 2.4 14 .60 30.75 Gray. 1910 2.4 14.20 28.60 . Gray . . 

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A PRELIMINARY REPORT ON CLAYS OF FLORIDA 179 Ries1 reports a white calcareous clay outcropping on the property oi W. B. Stoutatnire, eighteen miles southwest of Tallahassee, Sec. 1, 'f . 1 S . , R. 4 W., and a brick-clay on the property of J. D. Stoutamire in Sec. 15, T. 1 S., R. 4 W. This last clay, according to the same investigator, has good plasticity, 40 per cent of water of plasticity, 17 per cent air shrinkage, 5 per cent fire-shrinkage at cone 0-5, and tensile strength ranging from 175 to 210 pounds per square inch. Incipient fusiori begins at cone 05_ and the clay burns to a hard, dense product at c9ne 2 . Its color is a very light buff. Ries2 reports a calcareol:ls clay also on the property of W. W. Will iams, about one-half mile southeast of Jackson Bluff, on the Ocklocknee River, in Sec. 21, T . 1 S . , R. 4 W. The clay outcrops in the bed and along the sides of a small creek. The material is overlain by about five feet of sandy alluvium, and two and one-half feet thickness of clay is . . exposed. This clay has 45 per cent water of plasticity, 16 per cent airshrinkage, tensile strength ranging from 300 to 388 pounds per square inch with an average of 338, 5 per cent fire-shrinkage at cone 01 and 1'2 per cent at cone 5. Vitrification seemed to occur at about cone 6 and viscosity at cone 8. None of these clays can be used alone in the manufacture of clay products. The air-shrinkage of the J. D. Stoutamire clay and the Will iams clay is too high, but if sand or. other clays are added to reduce shrinkage a light-colored face brick may be made. A bluish-black, very plastic clay is exposed in Double Creek in the southwest corner of Sec. 8, T. 1 'S., R. 3 W., on the property of Hugh Black. The clay is three feet in thickness, is overlain by soil and ranging from six to twenty feet, and overlies a marl. This clay likewise has a high air-shrinkage. None ofthe clays of this Jackson Bluff region may be considered as of commercial importance at the present .time as no transportation is nearer than about eighteen miles. The chemical analyses of the Stoutamire and Wiliiams clays are given below: 1Ries, H., Clays of United States East of Mississippi River, U. S. Geological Survey Prof. Paper No. 11, p. 83, 1903. 2Loc. Cit. 

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180 FLORIDA GEOLOGICAL SURVEY-I 5TH ANNUAL REPORT Chemical Analysis of W. B . Stoutamire Clay, H. Ries, Analyst1 • , Silica (Si02) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35.95 Alumina (AI203) .................... ...... ; . . . . . . . . . . . . . . . . . . 13.23 Ferric Oxide ( Fe203) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.27 Lime ( CaO) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15.00 Magnesia <MgO) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.40 Water (H20) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10.55 Carbon Dioxidl! ( C02) .............. , ......... : . . . . . . . . . . . . . . . 18.50 Total . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99 . 80 Chemical Analysis of W. W. Williams Clay, H. Ries, Analyst2. Silica ( Si02) .. ................. ... ........................... : 30.83 Alumnia (AI203) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15.40 Ferric Oxide (Fe203) ............. :. . . . . . . . . . . . . . . . . . . . . . . . . . . 1.40 Lime (CaO) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13.78 Magnesia (MgO) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 .50 Water (H20) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.16 Carbon Dioxide (C02)" .. .. . . . . .. . . .. .. . .. .. .. . . .. . .. . . . . . . . . . . 20 . 14 Total 96.21 LEVY COUNTY Levy County borders the Gulf of Mexico in the northern part of t . he peninsula and is chiefly underlain by the Ocala formation, on which are a few outliers of the Alum Bluff and Alachua formations. Numerous lacustrine deposits, usually formed in sinks, are locally present. Residual clays from the Ocala limestone are common in the north ern and eastern parts of the county. Some of these residual deposits are quite extensive in area and of fairly uniform thickness. One such deposit is found at Williston where the clay is somewhat sandy, is red-burning, and has excellent working qualities . It may be used for common structural materials, but a vitrified product cannot be produced as its porosity remains high at the higher temperatures. A sample taken in the street in front of the Williston School building has the following physical properties : Physical Properties of Williston School Clay (Lab . No. o-9). Plasticity, judged by feel ...... .... . Water of plasticity ................ . Pore water ...................... . Shrinkage water ................. . Linear air shrinkage .............. . Volume air shrinkage ............. . Modulus of rupture, average ...... .. Slaking test ........... : .......... . Excellent. 31.20% 1.69% 29.51% 12.60% 35.75% 232.1 pounds per square inch. 2 minutes . lU. S. Geol. Survey Prof. Paper No . 11, p. 82, 1903. 2U. S. Geol. Survey Prof. Paper No. 11, p . 82, 1903 . 

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A PRELIMINARY REPORT ON CLAYS OF FLORIDA 181 Fire tests: Temperature. Linear Shr. Absorption. Porosity. Color. Per Cent. Per Cent. Per Cent. 950C. 2.4 18.10 32.50 Red. 1050 2.4 18.00 32.20 Red. 1150 4.9 14.75 31.90 Red. 1190 5.4 14.80 30.50 Red. 1230 5.9 13.10 28.20 Red. 1310 6.4 12.80 23.20 Red. n1any of these residual clays are adapted to the manufacture of products, it is to be noted that a great many others are not. The light-yellpw or buff raw clays quite free from sand, found in many places in this region, are, as a rule, unfitted for burned products. A white, plastic clay, free from sand, is encountered at a depth of thirty-nine feet on the property of J. H. Link, at Bronson. A white, plastic clay also underlies portions of the region about Chiefland at a depth of twenty or more feet. . Samples adequate for testing were not available. A yellowish-white calcareous clay is found underlying portions of Inglis, but its lime content is too high for use in burned products. LIBERTY COUNTY Liberty County lies in middle Florida between the Ocklocknee and FrG. 27.-Clay e x posed on the Apalachicola River at Estiffariulga Bluff, Liberty County. 

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182 FLORIDA GEOLOGICAL SURVEY-15TH ANNUAL REPORT Apalachicola rivers. Its surface exposures are sands, clays and tnarls of the Alum Bluff, Choctawhatchee and Pleistocene formations. Flood-plain clays are common along the Ocklocknee and Apalachi-: cola rivers. Two of . these clays are found at Estiffanulga Bluff on the A ' palachicola River. The section here is as follows: Section at Estiffanulga Bluff, Apalachicola River. Feet. Soil ............ . ................................. ..... . Clay (Top, Lab. Sample No . 0-39)........................ 20 Sand . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 Clay (Bottom, Lab. Sample No. 0-46) . . ................... 5 plus Inchu. 8 Only five feet of this lower clay are exposed above the river level. Its exact thickness is not known. Both of these clays are highly micace ous. Neither of them have been worked. The Apalachicola River offers water transportation to points northward and southward. The top clay has excellent plasticity, working and drying qualities and to a light-red color at cone 010. This clay may be used for common face brick, hollow-block ware, drain tile and red earthen ware. Its physical properties are as follows : Physical Properties of Estiffanulga Bluff Top Clay (Lab. No. 0-39). Plasticity, judged by feel. ......... . Water of plasticity .... . . . .......••• Pore water . ..................... . Shrinkage water ........... ...•..• Linear air shrinkage .............. . Volume air shrinkage ............. . Modulus of rupture, average ....... . Slaking test ..................... .. Steel hard at cone OS. Fire tests: Temperature. Linear Shr. Absorption. Per Cent. Per Cent. 950C. 1.9 23.55 1950 3.9 23.45 1150 6.9 14.95 1190 5.9 9 .23 1230 5.9 9.39 1310 11.9 5.78 Excellent. 30.65% 0.45% 30.20% 9.10% 29.20% 281.8 pounds per square inch. 20 minutes. Porosity. Color. Per Cent . 41.30 Brick red. 40.75 Brick red. 30.90 Brick red. 20.75 Brick red. 21.10 Brick red. 15.75 Brick red. The lower clay is also highly plastic and has excellent working and drying qualities. It is cream-burning up to cone 12 where it changes to a gray. This clay may be used for stot:Ieware and terra-cotta as weil as a good grade of structura1 n1aterials. It has the following physical prop erties: 

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A PRELIMINARY REPORT ON CLAYS OF FLORIDA 183 Physical Properties of Estiffanulga Bluff Bottom Clay (No. 0-46). Plasticity, judged by feel. . . . . . . . . . . Excellent. Water of plasticity.......... . ...... 29.45% Pore water . . . . . . . . . . . . . . . . . . . . . . . 0.45% Shrinkage water . . . . . . . . . . . . . . . . . . 29.00% Linear air shrinkage............... 8.30% Volume air shrinkage.............. 31.05% Modulus of rupture, average..... . . . 570.9 pounds per square inch. Slaking test . . . . . . . . . . . . . . . . . . . . . . . 24 hours. Steel hard at cone 05. Fire tests: Temperature. Linear Shr. Absorption. Porosity. Color. Per Cent. Per Cent. Per Cent. 950C. 2.7 19.71 35.60 Cream. 1050 3.2 19.87 36.00 Cream. 1150 6.7 11.61 25.20 Cream. 1190 6.7 9.05 19.30 Cream. 1230 6.7 7.10 15.80 Cream. 1310 6.7 4.53 10.60 Cream. 1370 7.2 2.52 6.70 Gray. 1430 8.2 1.29 3.65 Gray. MADISON COUNTY Madison County lies in north Florida . between the Suwannee and Aucilla rivers. It is underlain by Alum Bluff and Chattahoochee formations. A mantle of red, sandy clay covers practically all of the county, but no clays suitable for manufacturing purposes are known. MANATEE COUNTY -Manatee County is situated south of Tan1pa Bay on the west side of the peninsula. Its surface exposures are chiefly the Alum Bluff and Bone Valley formations. The H. A. Graack and 'Sons Pottery in Bradentown uses a sandy clay dredged from the 1v1anatee River. The clay is washed by hand before using. A white, calcareous clay occurs east of Br:adentown and occupies a more or less continuous area eastward to the vicinity of Gardner and Arcadia. An exposure on the property of W. J. McLaughlin, eight and one-half miles east of Bradentown, Sec. 28, Twp. 34 S., R. 19 E., shows the following section : Section Exposed in Creek near Satwmill qn W. J . McLaughlin Property. Feet. Inches. Soil ................................................. : .. 18 Clay, white (Lab. Sample No. 0-72) ................ ... .. 4 6 Clay, white (Lab. Sample No. 0-19)...................... 24 plus 

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184 FLORIDA GEOLOGICAL SURVEY-151':8; ANNUAL REPORT Both of the s e . clays are and a porous tex ture up to their fusion points. The top clay melts at cone 12 and the lower one at cone 9. Neither of them are desirable for the manufacture of high-grade clay products. A light, so(t, porous structural material of low strength ma y be made from the lower clay, but very careful grinding and . mixing would . be n e cessary. Both of these clays are high it;1 soluble salts. The upper one contains 24.4 per cent lime and 6 . 613 per cent mag nes i a, as may be s een fron1 the analys i s given on the next page . Its physical properties are : . . Physical Propert ies of W. J . McLaughlin Top Clay (Lab . No. o-72). Plasticity, judged by feel .... . : . . . . :. . Water ot plasticity... . . ............ 29.10% Pole water . . . . . . . . . . . . . . . . . . . . . . . . 0 . 19% Shrinkage wate r . . . . . . . . . . . . . . . . . . 28.91% Linear air shrinkage. . . . . . . .. . . . . . . . 4 .80% Volume air shrinkage . . ...... . ..... 12.10% Modulus of rupture, average. . . .... . 265.9 p'er square inch . Slaking test .... . • . • . . . . . . . . . . . . . . . 10 m . inutes . Overfires at cone 12. Fire Temperature. Linear Shr. Absorption . Porosity. Color. Per Cent. Per Cent. Per Cent. A 950C. 0.8 6.19 6.7.20 Cream. 10'50 1.2 5 .87 66.80 Cream . 1150 2.2' 5 .30 63.50 Cream. 1190 5.2 3.87 54.50 Cream. 1230 . 3 . 2 3 .93 57.50 Cream. 1310 2.2 4.05 60.10 Cream. lower day contains 9.1 per cent lime . and 5.-54 per cent mag nesia, . as m _ ay be seen from the analysis giyen below. Its physical properties are: . . Properties of W. J . McLaughlin Bottom Clay (Lab. No . Plasticity , judged by feel... . . . . . . . • • Excellent . Water of plasticity •..... . . . ;....... 38.40% Lhie .ar air shrinkage. . . . • . . . . . . . . . . 12.70% Volume air shrinkage. . . . . . . . . . . . • . 3 6.9 5% Modulus of rupture, average. . . . . . . . 544 . 9 pourids pe r square inch . . Slaking test . . . . . . . . . . . . . . . . . . . . . . . 3 days. Overfires at cone 9. Fire tests: Temperature. LinearShr. Absorption. Porosit'y. ... Per Cent. Per Cent. Per Cent. 950C. 0.2 26.4.:5 48.75 Cream. 1050 2.3 26.20 47.50 Cream. 1150 4.8 25.80 , . 43.30 Cream. 1190 4 . 3 20 .75 43.40 Cream. 1230 . 6.3 16.75 

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. A PRELIMINARY REPORT ON CLAYS OF FLORIDA 185 Chemical Analysis of W . J. McLaughlin Clays, A.M. Henry, Analyst. Lab. Numbers. O-I9 0-72 Silica ( Si02) . . . ................................... . Iron and AI uminum oxides ............... ....... ... . Calcium oxide ( CaO) ................... .. . . .... . 54.95 34.55 11.54 9 . 10 24.40 Magnesium oxide ( MgO) . ............... ......... . . Moisture at 100C . ............ ...................... . 5.54 6.63 4 . 37 1.70 Both samples contain considerable organic matter. 85.50 73.03 The Bartow clay occurs in the northeastern part of the county . (For a discussion of Barto . w clay see Polk County, page 195 . ) This area, h9wever, is not accessible to Fuller's earth occurs in the Alum Bluff formation and is mined at Ellenton on the north side of the Manatee River. MARION COUNTY Marion County is situated in the central part of the peninsula. Its western half is underlain chiefly by the Ocala and the eastern half by the Alum Bluff forn1ation . Numerous outliers of the Alum Bluff and Alachua formations are found in the Ocala formation. The part of the county extends to Lake George in the St. Johns River valley and includes flood-plain deposits. Marion County is partly in the Lake Region, and numerous lacustrine deposits, chiefly in sink-holes, are found locally. Residual clays fron1 the Ocala limestone are of common occurrence but few of them are of commercial importance . The losses from warping and cracking in drying and firing these clays are often excessive. In the northwestern part of the county, just across the county line f . rom Williston . in Levy County, are some clays having the prop ertie s as the Williston Scho o l cla y . (See Levy Count y , page 180 . ) Cal careous residual clays are found near Dunt?-ellon, Summerfield, and l(endrick. Sedimentary clays underlie extensive areas in the eastern part of the county. One of these is found in the region about Burbank . Here the clay is over . eighteen feet deep and overlain by about one foot of sandy soil. The exact depth of the clay is not known. This clay is red-burning, has good plasticity, works . well and dries without difficulty. It may be used for common hollow-block ware, 

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186 FLORIDA G E OLOGICAL SURVEY-15TH ANNUAL REPORT fireproofing a nd drain tile. The is slightly sandy and retains a dis tinctly porous te x tUre at cone 16, hence a vitrifi e d product could not be \. . s atisfactorily produced . A sample taken one-half mile south of Burbank on the Ocala Northern Railway has the following physical properties: Phys i cal Properties of the Burbank Clay (Lab. No. o-20) . Plasticity, judged by feel... . . . . . . . . Excellent. Water of plasticity................ . 23.20% L inear air shrinkage . . . . . . . . . . . . . . . 10.60% Volume air shrinkage. . . . . . . . . . . . . . 24.85% Modulus of rupture, average. . . . . . . . 279.3 pounds per square inch. Slaking test .......... . ... . . . . . . . . . 20 minutes. Fire tests : T e mp e r a t u re. Linear Shr. Absorption. Poros i ty. Color. Per Cent . Per Cent. Per Cent. 950 C . 0 .. 1 13.20 31.95 Brick red. 1050 0.6 14 . 10 29. 20 Brick red. 1150 0.6 12.40 29.75 Brick red . 1190 0 . 1 10.95 28.95 Brick red. 1230 1.4 10.42 28 . 20 Brick red. 1310 2 . 1 10.14 27.75 Brick red. 1370 10.07 26.85 Brick red. A lacustrin e cla y underlies the region adjoining Lake Weir on the south. It is grayish to white in color, varies in thickness from three to seven feet, and is overlain by sand ranging from three to six feet in thick ness. While clay is only about one-half mile from a Seaboard spur, the heavy overburden precludes the deposits having any commercial value. Coarse, sandy clay, suitable for sand-clay road rrmterial, is found in the southeastern part of the county. MONROE COUNTY Monro e County lies at the extreme south end of the peninsula and consi s ts chiefly of Pleistocene limestone and sands. No clays are known in the county. NASSAU COUNTY Nassau County is situated in the extreme northeast corner of the and lies between the St. Marys River and the Atlantic Ocean. The county underlain mostly by sands and marls , but the central part of the has some clay deposits. Flood-plain clays are found along the St. Marys River. 

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A PRELIMINARY REPORT ON CLAYS OF FLORIDA 187 FIG . 28.-"0id Brick Yard Landing" on the St. Marys River, Nassau County. Formerly the site of a brick plant. Frc. 29.-Loading cars, Callahan Brick and Tile Co., Callahan, Nassau County. 

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188 FLORIDA GEOLOGICAL SURVEY-15TH ANNUAL REPORT The Call a h a n Brick and Tile Company works a deposit, probably marine, ranging from eight to t we nty feet in thicknes s and having an overburden of six or eight inches. This deposit is underlain .in places by a marl. About twenty acres have been worked and about twenty acres more have been proven . The deposit probably underlies a much more extensive area. The pl .ant is located on the Seaboard Air Line Railway near its in tersection with the Atlantic Coast Line Railroad . The product is shipped to point s in south and west Florida . Both a common and a face brick are This clay may be used for con1mon structural materia l s where a vitrified product i s not essentiaL T . he fired product retains a porous tex ture at cone 15 . Its physical properties are: Physica l Properties of Callahan C(ay (Lab. No. o-29). Plasticity, judged by feel . ......... . Water of plasticity ................• Pore water ....................... . Shrinkage water ...... . .......... . Linear air shrinkage ........ . .... . . Volume air shrinkage .... . ........ . Modulus of rupture, average ....... . Slaking test . ... .............. .... . Fi r e tests: Temperature. Linear S!Jr. Absorption. Per Cent. Per Cent. 950C . 0 . 7 15.85 1050 1.3 15.70 1150 1.8 14.15 1190 2 . 2 1 2.60 1230 2 . 2 11.95 1310 2.2 11.58 25.60% 0.42% 25.18% 11.70% 29.85% 805.2 po unds per squa r e inch. 3 days. Excellent. Porosity . Color. Per Cent. 39.75 Brick red. . 39.00 Brick red . 31.48 Brick r ed. 30.25 Brick red. 28.00 Brick r ed. 26.75 Brick red. A brick plant was formerly operated by. the Callahan Brick and Tile Company about three-quarters of a mile south of Callahan. The clay \ worked is the same as is now being -worked at Callahan. The region northward between Callahan the St. Marys River is practically a ll underlain . by a slightly sandy clay. A bri ck plant was formerl y opera ted at the "Old Brick Yard Land ing" on the St. Marys River, which is about forty miles west of Fernan dina. Here there is an overburden of six to eight inches of soil, two feet of weathered, reddish clay, then a considerable depth of a grayish, plastic clay. Wells n earby indicate that this clay has a thickness of approxi -

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A PRELIMINARY REPORT ON CLAYS OF FLORIDA 189 mate1y forty feet . Water transportation via the St. Marys River is available at this point. Other brick plants have been operated about seven miles east of Callahan, at Yulee, and at Fernandina. OKALOOSA COUNTY Okaloosa County is located in western Florida and extends from the Florida-Alabama line to the Gulf of Mexico. The formations consist of the Alum Bluff in the northeast corner and undifferentiated sands and marls in the remainder of the county. Much of the surface is covered by a sand-clay mantle. No days adapted to manufacturing uses are known in the county. 0KEECHOBEE COUNTY Okeechobee County lies just north of Lake Okeechobee artd east of the Kissimmee River. Pleistocene sands and marls form the surface materials. No clays of commercial i mportance are knowri to . be present. ORANGE COUNTY 9range County is sit uated in the east-central part of the peninsula and lies within the Lake Region . . Its surface fonnations are Alum Bluff and sands and marls. Reddish and brownish sandy clays suitable only for sandcla y roads are of widespread distribution in the county. A blui sh-gray cla y occurring about two miles east of Clarcona has been washed and found fairly satisfactory for some grades of work at the Orlando potteries. The overburden ranges from one to five feet of sand and the clay averages abouf three feet in thickness. The nearest railway is about two tniles. The unwashed clay has the foliowing physicaJ properties : . Physical Properties of the Clarcona Clay (Lab. No. o-6o). Plasticity, judged by feel. ......... . Water of plasticity ................ . Pore water ....................... . Shrinkage water, ...... ........... . Linear air shrinkage .............. . Volume air shrinkage .............. . Modulus of rupture, average ....... . Slaking test ...................... . Excellent. 22.50% 0.16% 22.34% 6.90% 19.80% 133.1 pounds per square inch. 3 days. 

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190 FLORIDA GEOLOGICAL SURVEY-I 5'I'H ANNUAL REPORT Fire tests : T e mperature. 950C. 1050 1150 1190 1230 FIG. 30.-0rlando P ot t ery, Orlando, Orange County. FIG. 31.-A potter at work, Orlando P o tt e ry, Orlando, Orange County. ' Linear Shr. P e r Cent. 0 . 6 1.1 1.6 3.1 4.1 Absorption. Per Cent. 19.57 20.52 18.93 16.47 15.31 Porosity. P er Cent. 37.40 38.80 35.80 32.80 33.10 Color. Cream. Cream. Cream. Cream. Cream. 

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A PRELIMINARY REPORT ON CLAYS OF' FLORIDA 191 Flood-plain clay s are exp os ed on the bank of the Econlockhatchee River, seven and one-half tniles east of Winter Park, on the property of P . A. J . Nelson. A section of this expo sure is as follows: S ec tion of Clay Strata on Eco nlocklzatclue River on N elso1z Property, East of Winter Park. F ee t . Sand, surface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 Clay, brown, plastic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 Clay, brown, sandy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 Clay, gray, jointed. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 Sand . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . ? This depo s it is located about two miles from the Florida East Coast Railway. The heavy overburden and the thickne ss of the clay does not warrant commercial exploitation. Nrumerous lacustrine deposits are found in Orange County. One of these, suitable for common brick, is exposed on the west side of Lake Ola, but its distance frotn transportation renders it of doubtful com mercial importance. A from city pit in the city of Orlando was tested by the United States Bureau of Standards in 1914 with the following re su lt s :1 Physical Properties of Orlando City Clay (Bureau of Standards Sample No. 14). PI astici ty. . . . . . . . . . . . . . . . . . . . . . . . . . Poor. Water of pl asticity............... . . 19.9 % Linear air shrinkage ............ , . . 2.55% Fire tests: Temperature. Linear Shr. Porosity. Color. Per Cent. P e r Cent. 950C. 0.56 36.1 Red. 1020 36.4 Red. 1050 34.6 Red. 1080 35.2 Red. 1100 35.3 Red. 1110 0.41 Red. 1140 35.2 Red. 1170 35. 8 Red. 1 200 35.6 Red. 1230 0.58 35.3 Red. 1260 36.4 Red. 1290 36. 0 Red. 1320 0.56 35.2 Red. This clay is of no value for the manufacture of clay products. OSCEOLA COUNTY Osceola County lies in southeastern edge of the Lake Region and is underlain by Pleistocene sands and marls. A few clays are in1Sel1ards, E. H., Report on Tests for Paving Brick, Florida Geol ogica l Survey Press Bulletin No. 7, 1915. 

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192 FLORIDA GEOLOGICAL SURVEY-I 5TH ANNUAL REPORT terbedded with the marls. Few of the se; however ; have sufficient thick ness and extent to warrant commercial exploitation. A brick plant was formerly operated near the Fair Grounds at Kissimmee. The clay is suitable for only a poor grade of con1mon build ing-brick. The deposit is located on the Atlantic Coast Line Railroad. Its physical properties are: Physical Properties of Kissimmee Fair Grounds Clay. (Lab : No. o-6]}. Plasticity, judge. d by feel .......... . Water of plasticity ... ............. . Pore water-............ : .......... . Shrinkage water ................. . Linear air shrinkage ....... ....... . Volume air shrinkage ...... ....... . Modulus of rupture, average ....... . Slaking test ........... ............ . Fire tests : Temperature. Linear Slzr . 11 bsorption. Per Cent. Per Cent. 950C. 0.7 17.57 1050 0.3 . 1150 1.7 11.92 1190 2.3 10.09 1230 8.94 Good. 24.45% 0.30% 20.15% 4.70 % 15.75% 271.5 pounds per square inch. 1 hour. Porosity. Color. Per Cent. 38.80 Brick red. 40.10 Brick red. Brick red. 30.20 Brick red. 25.75 Brick red. PALM BEACH COUNTY Palm Beach County is located between Lake Okeechobee and the Atlantic Ocean. Its formations are Pleistocene limestones and sands . N : o clays of importance are known . to be present. PASCO COUNTY Pasco County is located on the west side of the central portion of the peninsula . The Tampa and Ocala formations compose the surface materials with a .very . coarse sand-clay of unknown age forming a m . antle of variable thickness over much of the county. The coarse, sandy clay is reddish to brownish in color and at times has relatively high clay content. It has a thickness of as much as thirty feet or more in the region southwest of Dade City and near San Antonio. of this material is now being used for molding sand. It is a.lso extensively u sed in the cqunty for sand-clay road material. It has no value for the manufacture of clay products. 

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A PRELIMINARY REPORT ON CLAYS OF FLORIDA 193 Sedimentary kaolin occurs in numerous places in the vicinity of Dade City and in at least one point near San Antonio. For a full discus sion of this clay see Chapter IX. A grayish-brown, sandy clay occurs on the property of the Crystal Springs Colony near Crystal Springs. It contains some cherty frag ments. This clay is red-burning and has good plasticity and working qualities. Soluble salts are present to a detrimental extent and form an irregular . white efflorescence on the ware when exposed to moisture. If precautions are taken to overcome the s oluble salts this clay may be used for a fair grade of comn1on brick, but the production of a vitrified prod uct would be impracticable . Its physical properties are: Pl1ysical Properties of Crystal Springs Clay (Lab. No. o-69). Plasticity, judged by feel....... . ... Excellent. Water of plasticity................. 20.60 % Pore water .. . . . . . . . . . . . . . . . . . . . . . . 5.35% Shrinkage water . . . . . . . . . . . . . . . . . . 15.25% Linear air shrinkage............... 9 . 4 % Volume air shrinkage.............. 28.8 % Modulus of rupture, average....... . 317.7 pounds per square inch. Slaking test .. . . . . . . . . . . . . . . . . . . . . . 10 minutes. Fire tests : T emperature. Linear Shr. Absorption. Porosity. Color. Per Cent. Per Cent. Per Cent. 950C. 0.4 14.31 31.90 Brick red. 1050 0.6 13.40 32.80 Brick red. 1150 1.0 12.02 31.80 Brick red. 1190 1.0 12.39 30.40 Brick red. 1230 1.6 12.30 28.65 Brick red. 1310 2.4 12.98 22.80 Brick red. \ A gray, plastic clay occurs one mile north of Dade City, between the Seaboard track and the highway. This clay is irregular in extent, is underlain by limestone and averages about nine feet in thickness. The overburden consists of about two feet of sandy soil. This clay has a high air-shrinkage and cracks badly in drying and burning. It is not desirable for the manufacture of burned products. Its physical properties are: Physical Properties of Seaboard Clay, Dade City (Lab. No. o-22). Plasticity, judged by feel .......... . Water of plasticity ................ . Linear air shrinkage .............. . Volume a-ir shrinkage ............. . Modulus of rupture, average ....... . Slaking test ........... . .......... . Overfires at cone 9. Fair. 52.90% 13.90% 40.45% 180 pounds per square inch. 3 minutes. 

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194 FLORIDA GEOLOGICAL SURVEY-15TH ANNUAL REPORT Fire tests: Temperature. 950C. 1050 ' 1150 1190 1230 LinearShr. Per Cent. 3.1 3.1 4.1 4.1 5 .1 Absorption. Per Cent. 8.92 9.10 8.25 7.45 6.60 Porosity. Per Cent. 23.20 21.50 20.45 16.00 14.50 PINELUS COUNTY Color. Salmon. Salmon. Gray. Gray. Gray. Pinellas County is located on the Pinellas Peninsula, which lies between Tampa Bay and the Gulf of Mexico. It is underlain by sands and marls with some interbedded clays of the Tampa, Alum JUuff and Caloosahatchee formations. Some phosphatic clays are on the Gulf coast and in Curlew Creek north of Dunedin. These are not suited for use iri the manufac ture of burned products. A gray, sandy clay is _ found Alligator Creek, one-half . mile west of Coachman on the Tampa and Gulf Coast Railroad. The clay is approximately twenty-four feet thick and is overlain by tthree feet of sand. This clay may be used for the n1anufacture of a fair grade of common brick. A vitrified product, 11owever, could not be produced . A bluish-gray clay is exposed at the edge of Old Tampa Bay and extends around to the vicinity of Safety Harbor. This cl_ ay contains organic matter and some soluble salts and swells badly upo _ n firing. POLK COUNTY Polk County is situated in the south-central part of the peninsula. The Alum Bluff and Bone Valley formations comprise the chief surface materials. --The northern and eastern part of the county has a heavy coating of coarse, sandy clay, suitable only for sand-clay road material. The Bartow clay, the sandy clay stratum overlying the Land Pebble Phosphate horizon, is of widespread occurrence in the southwestern part <?f the county. The terJJ?., Bartow clay, was formerly applied to the matrix carrying the pebble phosphate, but now the application of this term is limited to the sandy clay overlying the phosphate horizon. It is removed as overburden in the phosphate mines of this region. The Bartqw clay ranges in thickness from three to twelve feet. Its high sand content. renders molding and handling difficult. This clay may be used only in the manufacture of common brick. It makes a porous, 

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A PRELIMINARY REPORT ON CLAYS OF FLORIDA 195 buff-colored product at cones 010 and 05, arrd burns to a more dense texture and reddish color at cone 1. It fuses at cone 5. Several samples of the Bartow clay were examined. These indicate that it is very unifonn in its physical properties . The following sample taken frotn one of the phosphate nunes near Bartow has the following physical properties: Physical Properties of t!ze Bartow Clay (Lab . No. o-SJ). Plasticity, judged by feel........... Fair. Water of plasticity................. 20.10% Pore water .. . . . . . . . . . . . . . . . . . . . . . . 0.00% Shrinkage water . . . . . . . . . . . . . . . . . . 20.10% Linear air shrinkage. . . . . . . . . . . . . . . 5.00% Volume air _shrinkage.............. 11.20% Modulus of rupture, average........ 195 . 3 pounds per square inch. Slaking test . . . . . . . . . . . . . . . . . . . . . . . 24 hours. Steel hard at cone 3. Over.fires at cone 5. Fire tests: Temperature. Linear Shr. Absorption. Porosity. Color. Per Cent. Per Cent. Per Cent, 950C. 0.00 18.57 37.10 Buff. 1050 0.00 16.38 36.00 Buff. 1150 0.00 12.84 31.20 Gray. 1190 3.00 10.60 27. 00 Gray. 1230 3 . 00 Gray. Numerous lacustrine deposits are found throughout the eastern part of the county . These deposits are usually local and of limited extent. In the eastern part of the county is a well-defined, irregular ridge, extending from Haines City southward beyond Frostproof. Imn1ediate ly west of this ridge are several thin sedimentary clays. strata frequently have considerable areal extent, but they are too thin to warrant commercial exploitation. A section made on the Highlands Farms, four miles north of Lake ' \ Na les, which w ill serve as an exa1nple, is as follows: Section Made in Clay-Bearing Strata on Highland Farms, Lake Wales. Feet. Inches. Sand . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 Clay, gray, sandy ............................. : . . . . . . . . . . 1 C la y, grayish red . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 Clay, gray, sandy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 C la y; gray, j o inted . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 6 S ' and, red . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ? 

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196 FLORIDA GEOLOGICAL SURVEY-15TH ANNUAL REPORT Two sandy clays occur at the-"Y" on the Seaboard tracks as they enter Lake Wales. A section here is: Section of Clay Strata at Seaboard uyn at Lake Wale s. Sand ..... .... ... ................. .. ........... ........ .. ......... Clay, gray, sandy . ..................... ............... ........... . Clay, black ............................................. : . ...... . Feet 3 5 3 These two clays have sin1ilar properties. Both are sandy and are suited for nothing more than a very poor grade of common brick. The black, lower clay has the following physical properties: Physical Properties of Seaboard uyn Black Clay) Lake Wale s (Lab. No. 0-51). Plasticity. . . . . . . . . . . . . . . . . . . . . . . . . . Fair. Water of plasticity. . . . . . . . . . . . . . . . . 19.50% Pore water .............. . : . . . . . . . . 0.63% Shrinkage water . . . . . . . . . . . . . . . . . . 18.87% Linear air shrinkage. . . . . . . . . . . . . . . 6 .90% Volume air shrinkage. . . . . . . . . . . . . . 15.30% Modulus of rupture, average........ 135.3 pounds per square inch. Slaking test .. . . . . . . . . . . . . . . . . . . . . . 24 hours. Fire . tests: Temperature. Linear Shr. Absorption. Porosity. Color. Per Cent. Per Cent. Per Cent. 950C. 1.9 15.80 33.75 Cream. 1050 2.5 15.58 34.40 Cream. 1150 2.9 14.68 32.60 Cream. 1190 2.9 14 .54 31.60 Cream. A sample of clay from the Peace Valley Farms Cotnpany's prop erty, near Winter Haven, was tested by the Bureau of Standards in 1914.1 The results indicate that this clay is suitable only for. a poor grade of common brick. Its physical properties are : Physical Properties of Peace 17 alley Farms Clay) Bureau of Standar'ds. (Sample No. 22). Plasticity; judged by feel... . . . . . . . . Fair. Water of plasticity................. 24.9 % Linear air shrinkage. . . . . . . . . . . . . . . 6.28% !Sellards, E . H., Report on Tests for Paving Brick, Florida Geol. Survey Press Bulletin No. 7, 1915. (Bricks were made some twenty years ago from a whitish marly clay just east of Carter's on the Atlantic Coast Line, near the head of the Peace River, but the venture does not seem to have been a success. R. M. Harper.) 

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A PRELIMINARY REPORT ON CLAYS OF FLORIDA 197 F i re tests: Temperature. Linear S!Jr. Absorption. Porosity. Color. Per Cent. Per Cent. 950C. 0 . 37 35.6 Red. 1010 35.8 . Red. 1040 35.6 Red. 1070 36.0 Red. 1100 0.47 34.8 Red . 1130 33.8 Red . 1160 33. 8 Red. 1190 33.7 Red. 1220 0.08 33.6 Red. 1250 33.7 Red. 1280 33.4 Red. 1310 0.24 33.6 Red. PUTNAM COUNTY Putnam County lies in the St. Johns River valley in the north eastern part of the State. The western part of the county is underlain by the Alum Bluff formation. Pliocene and Pleistocene sands and marls underlie the eastern part of the county. Flood-plain clay deposits are cotnmon along the St. Johns ;River. Lacustrine deposits are widely scattered over the county. The sedimentary kaolin occurs at several points in the southwestern part of the These are described in Chapter IX. Several brick plants have formerly been operated in the region around Palatka. The clays were all St. Johns R{ver flood-plain clays. A clay formerly worked by the Utica Brick and Tile Company at Rice Creek Station tnay be used for con1n1on brick, face brick, hollow blocks, fireproofing, and drain tile. This deposit adjoins the Atlantic Coast Line Rai lroad and is located about 100 yards south of the station. Its physical properties are: Physical Properties of Rice Creek Station Clay (Lab. No. o -p). Plasticity, judged by feel .......... : Water of plasticity ................ . Pore water ....................... . Shrinkage water ................. . Linear air shrinkage .......... . . .. . Volume fire shrinkage ............. . Modulus of rupture, average ..... .. . S laking test .......... . . .......... . Excellent. 24.20% 0.50% 23.70% 7.7% 30.5 % 776.3 pounds per square inch . 6 hours. 

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198 FLORIDA GEOLOGICAL SURV EY-I 5TH ANNUAL REPORT Fire tests: Tempe rature . Linear SIJr. Absorption. Poros ity. Color . Per Cent. Per Cent. Per Cent. 950C. 0.2 12.26 30.40 Brick red. 1050 0.3 13.92 30.60 Brick red. . 1150 0.3 12.55 28.00 Brick red. 11'90 0.3 11.60 26.00 Brick red. 1230 1.3 10.83 26 . 40 Brick red. 1310 11.50 28 .60 Brick red. 1370 11.01 28.00 Brick red. 1430 8.19 19.10 Brick r.ed. The old Herman . Brown brick plant was located on Rice Creek, about three miles sout h wes t of Rice Creek in Sec . 16, T. 9 S. , R. 26 E. Common brick, hollow block and drain tile were produced. This deposit is located miles west of the Atlantic Coast Line Rail road a . nd two mile s north of the Georgia and Florida Rail road. The abandoned plant was located on the bank of the creek which offers water transportation facilities to Jacksonville and other points on the St. Johns River. The clay is feet thick, underlain by sand and has an over burden of about one foot of soil. The exact extent of this deposit is not known, but more than forty acres are known to be underlain by it. A vitrified product cannot be produced, but this clay is suitable for the manufacture of a good grade of st ructural materials. Its physical properties are : Physical Properties of Herman Brown Clay, Rice Creek (Lab. No. o-62). Plasticity, judged by feel : ......... . Water of plasticity ................ . Pore water •. ..... ................ . Shrinkage water ..... . ........... . Linear air shrinkage .............. . Volume fire shrinkage ..... ....... . Modulus of rupture, average ....... . Slaking test ...................... . Excellent . 22.25% 1.32% 20.93% 10.0% 26.45% 546.2 pounds per square inch . 3 hours. 

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A PRELIMINARY REPORT ON CLAYS OF FLORIDA 199 Fire tests: Temperature. 950C. 1050 1150 1190 1230 1310 Linear Shr. Per Cent. 0.5 1.0 2.0 2.6 2.1 3.0 Absorption. Per Cent . 13.11 13.12 13.23 11.08 11.79 12.34 Porosity . Per Cent. 36.50 36.20 34.16 31.70 28.70 30.70 Color . Brick red. Brick red. Brick red. Brick red. Brick red. Brick red. A similar clay exposed about one-half mile north of Springside, Sec. _ 29, T . 9 S., R. ' 26 1E., may also be used for a good g rade of structural materials. It has an overburden of about one foot, ranges from twelve to twenty feet in thickness and underlies an ex _ tensive area in this region. T,his clay adjoin s the Georgia Southern and Florida Railroad at Springside. A sample taken one-half mile north of the station has the following physical properties : Plzysical Properties of Springside Clay (Lab. No. 0-#.). Plasticity, judged by feel .......... . Water of plasticity ................ . Linear air shrinkage .............. . Volume air shrinkage ............. . Modulus of rupture, average ....... . Slaking test ••..................... Overfires at cone 12 . Fire tests: Temperature. Linear Shr. Absorption. Per Cent. Per Cent. 950C. 0.1 12.60 1050 0.9 13.70 1150 0.6 12.31 1190 1.4 11.45 1230 1.4 10.44 1310 1.4 . 8.69 Excellent. 25.10% 11.1 % 28.57% 791.4 pounds per square inch. 1 hour. Porosity. Color. Per Cent . 29.70 Brick red. 31.00 Brick red. 29.40 Brick red. 29.75 Brick red. 25.75 Brick red. 17.50 Dark red. Numerous other good common-brick clays occur in the region be tween Crescent City and Lake George. A brick plant was formerly operated at Denver where a common brick was made. Some of these clays are very sim-ilar in properties to those west of Palatka, and others seem to be identical with the Shell Bluff clay, found on the opposite side of Crescent Lake in Flagler County . (See Shell Bluff Clay, p age 1 58.) Sandy clays, which may be used for a fair grade of common brick, are also found on the east side of the St. Johns River, near Orange Mills and San Mateo. 

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200 FLORIDA GEOLOGICAL SURVEY-15TH ANNUAL REPORT ST. JOHNS COUNTY St. Johns County lies in northeastern Florida, between the St. Johns River and the Atlantic Ocean. It is underlain principally by un differentiated sands and marls with a few interbedded clays of limited areal extent and thickness. Some good clays are found in the southwestern part of the county in the vicinity of Hastings : One of these occurs on the property of ]. T. Minton, about one mile southeast of Hastings. This deposit con sists of four feet of a gray clay overlain by one foot of soil. A tnarl un derlie s the clay. This deposit has been proven on forty acres at this place. This clay may be used for a good grade of comn1on and face brick. It may equally well be used for con1mon structtiral n1aterials. It has the following ph ys ical properties: Physical Properties of Minton Clay, Hastings (Lab. No. 0-33) . Plasticity, judged by feel. . . . . . . . . . . Excellent • . Water of plasticity. . . . . . . . . . . . . . . . . 23.55% Pore water . . . . . . . . . . . . . . . . . . . . . . . . 0.41% Shrinkage water . . . . . . . . . . . . . . . . . . 23.14% Linear air shrinkage. . . . . . . . . . . . . . . 11.2 % Volume fire shrinkage.............. 31.2 % Modulus of rupture, average........ 837.7 pounds per square inch. Slaking test •. . . . . . . . . . . . . . . . . . . . . . 2 minutes. Steel hard at cone 1. Overfires at cone 5. Fire tests: Temperature. Linear Shr. 11 bsorptiotz. Porosity. Color. Per Cent. Per Cent. Per Cent. 950C. 0 . 7 20.40 35.75 Brick red. 1050 1.2 11.40 27.40 Brick red. 1150 1.2 10.80 26.50 Brick red. 1190 2.2 8.55 25 . 50 Brick red. 1230 2 . 3 8.30 22.50 Brick red. Sandy clays occur along the east bank of the St. Johns River. These are flood-plain c1ays of variable extent and thickness and are suitable only for an inferior grade of common brick. One of these clays ex four miles east of Picolata on the St. Augustine road has the following section : Section of Clay Strata near Picolata. Soil ..... .................................. ..................... . Clay, red, sandy ............ ................................... . Sand, grayish with clay ......................................... . Feet. 1 10 ? 

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A PRELIMINARY REPORT ON CLAYS OF FLORIDA 201 A similar clay occurring on the property of J. J . Goss, near Riverdale, has the following physical properties : Physical Propertiu of J. J. Goss Clay, Riverdale (Lab. No. o-77). Plasticity, judged by feel .......... . Water of plasticity ................ . Pore water ....................... . Shrinkage water ................. . Linear air shrinkage .............. . Volume fire shrinkage ............. . Modulus of rupture, average ....... . S I a king test .... .................. . Fire tests: T emperature. 950C. 1050 1150 1190 1230 Li11ear Shr. Per C e11t. 1.0 1.5 2.5 2.5 2.5 A bsorptio1l. Per Ce11t. 28.98 27.72 20.48 19.30 19 .04 Excellent. 21.15% 0.40% 20.75% 6.5 % 16.1 % 211.9 pounds per square inch. 10 minutes. Porosity. Per Ce11t. 38.90 35.50 29.20 27 . 60 25.60 Color. Brick red. Brick red. Brick red. Brick red. Brick red. ST. LUCIE COUNTY St. Lucie County i s located just northeast of. Lake Okeechobee and borders the Atlantic Ocean. It is underlain by n1arls and sands of Pleistocene age. N o cla ys ofimportance are known. SANTA ROSA COUNTY . Santa Rosa County is s ituated in west Florida just east of the Escambia River and extends frotn the A l abatna boundary to the Gulf of Mexico. The surface forn1ations are sands, marls and clays, ranging from Pleistocene to Recent in age. The Citronelle formation underlies portions of the western part of the county. The clays of Santa Rosa County have, in .. the past, been practically unworked. This lack of devclopn1ent is largely due to the absence of trans portation facilitie s in tho s e sections of the county where the clays of greatest promise occur. The Louisville and. Nashvi lle Railroad traverses southern part af the county from east _ to west, and the Florida and Alabatna Railroad extends fron1 Milton northeastward into Alaban1a, but the clays most suitable for cotnmercial uses lie in the northwestern part of the county. The Board of Trus tees of t he Allentown Consolidated School Dis trict, nine n1iles north o f M ilton, have followed a novel procedure to 

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202 FLORIDA GE OLO GICAL SURVEY-15TH ANNUAL REPORT F ' 1 c . 32.-Portable press in operation. Allentown Consolidated School, near Milton, Santa Rosa County. provide brick for the erection of a n1odern school building. They have emplo ye d G. H. M urphy, of the Gle ndale Brick ' W orks, 91endale, to make for them 4 00,000 brick. They plan to use half of this brick in the censtruction of the building and s ell the remaining half to defray the expenses of manufacture. Mo r e than the 20 0,900 a llotment to be sold had been engaged b y local citizens at the time the sc heme was put into operation. Most of the work nece ssary in the manufacture of the brick is being donated by re s idents of the community. Mr. Murphy has ope!led up a clay-pit about one-half mile from the site of the school building . He is using a portable press and cutting machine which is drawn by a tractor. The tractor is also used to furnish the power when the press is in operation . Two are by scrapers and m<?lded ' itnmediately in the press. The green brick are stacked out in the open to dry with no protection whatever from rain, wind or sunshine and when dry are burned in temporary scove kilns of 50,000 capacity. Drying is completed in three days. Those interested in this enterprise are exceedingly fortunate in having a clay close at hand which can such rapid, crude and un-

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A PRELIMINARY REPORT ON CLAYS OF FLORIDA 203 protective treatment without serious losses. The percentage of loss here is incredibly low . • The clay deposit, which is probably the Citronelle formation, is sedi mentary and consists of two s trata. The upper one has a slight amount of sand, is brownish in color, and is about two feet in thickness. The lower one is gray in color, free from sand but has a slight amount of mica. Its thickness is unknown. The deposit is overlain by about two feet of sand and soil, which is ren1oved. The proportion of the two clays used in the A llentown brick is one part of the upper brown one to parts of the lo wer gray clay. This deposit of clay has an extensive distribution in this vicinity and probably is connected with deposits of similar clay farther westward in Escambia County. Either of these clays may be used for stoneware, terra-cotta, or roofing tile. The small amount of sand in the upper clay should be washed out before it is used for the better grades of ware. The upper clay has the following physical properties: Physical Properties of Allentown Top Clay (Lab. No. 0-Iif.}. Plasticity, judged by feel .......... Excellent. Water of plasticity. ................ 29.90% Linear air shrinkage. . . . . . . . . . . . . . . 8.6 % Volume fire shrinkage. . . . . . . . . . . . . . 24.2 % Modulus of rupture, average........ 324 .2 pounds per square inch. Slaking test . . . . . . . . . . . . . . . . . . . . . . . 20 minutes. Steel hard at cone 1. Fire tests: Temperature. Linear Shr. A b sorption. Porosity. Color. Per Cent. Per Cent. Per Cent. 950C. 0.9 20.20 38.90 Pink." 1050 1.6 17.10 33.25 Pink. 1150 6.9 8.55 19.80 Gray. 1190 6.9 7.08 17.25 Gray. 1230 6.9 6.85 15.60 Gray. 1310 8.9 3.14 8.85 Gray. 1370 9.9 1.55 8.45 Gray. 1430 9.9 1.12 4 .72 Gray. 

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204 F L ORIDA GEOLOGICAL SURVEY-15TH ANNUAL REPORT Frc. 33.-Parti a ll y built scove kiln in rear ground with freshly m olde d brick stacked out in open air to dry in foreground. A llentown Conso lidated School, t en m i les north of Milton, Santa Rosa County. Frc. 34.-Firing a scove kiln . Allentown Conso lidated School , ten mil es north of Milton, Santa Rosa County. 

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A PRELIMINARY REPORT ON CLAYS OF FLORIDA The lower clay has the following physical properties: Physical Properties of tlu A /lent own Lower Clay (Lab. No. o-81). Plasticity, judged by feel . . . . . . . . . . . Excellent. Water of plasticity................. 24.15% Pore water . . . . . . . . . . . . . . . . . . . . . . . 0.65% Shrinkage water . . . . . . . . . . . . . . . . . . 23.50% Linear air shrinkage... . . . . . . . . . . . . 8 . 0 % Volume air shrinkage.............. 30.6 % Modulus of rupture, average ..... :. . 244.6 pounds per square inch. Slaking test .. . . . . . . . . . . . . . . . . . . . . . 10 minutes. Steel hard at cone 1. Fire tests: Temperature. Linear Shr. Absorption. Porosity . Color. Per Cent. Per Cent. PerCent. 950C. 0.0 21.99 38.20 White. 1050 2.0 36.20 White. 1150 5.0 15.98 18.60 Brown. 1190 7.0 10.28 15.50 Brown. 1230 7.0 9.60 10.50 Gray. 1310 7.0 2.25 6.15 Gray. 1370 9.5 2.00 5.95 Gray. 1430 8.0 1.52 4 .75 Gray. 205 A sample of clay taken fron1 Blackwater Creek, two and one-half miles northeast of Milton, was tested by the Bureau of Standards in 1914.1 Its physical properties indicate that it n1ay be used for a good grade of comtnon structural tnaterials, but . not for a vitrified product. It has the following physical properties: Physical Properties of Blackwater Creek Clay (Bureau of Standards, Sample No .3). Plasticity. . . . . . . . . . . . . . . . . . . . . . . . . . Excellent. Water of plasticity. . . . . . . . . . . . . . . . . 28.9% air shrinkage. . . . . . . . . . . . . . . 6.0% Fire tests: Temperature. 850C. 950 980 1'010 1040 1070 1100 1130 1160 1190 1220 1250 Linear Shr. Absorption. Per Cent. 0.64 0.21 1.44 1.17 Porosity. Per Cent. 35.30 35.80 36.20 34.86 33.60 32.15 31.10 29.55 29.05 28.80 28.05 27.30 Color. Salmon. Buff. !Sellards, E . H., Report oh Tests for Paving Brick, Florida Geol. Survey Press Bulletin No. 7, 1915. 

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206 FLORIDA GEOLOGIC A L SURVEY-15TH ANNUAL REPORT SARASOTA COUNTY. Sarasota County is situated in southwe s t Florida and borders on the Gulf coast jus t above Charlotte Harbor. Its surface materials are chief ly sands and marls . No important clay d e posits are known within rea sonable distance from transportation. SEMINOLE COUNTY Seminole County is located in the ea s t-central part of the peninsula in the upper St. Johns Valley. Sandy s urface clays containing a co a r s e quartz sand and very desirable for s and-cla y road s are widely distribut e d over the county. No clays suitable for manufacturing products are known. SUMTER COUNTY Sumter County is located in the we s t-central part of the peninsula and is bordered on the west by the Withlacoo c hee River. The Ocala, Tampa and Alum Bluff formations compri s e the greater part of the surface materials. Thes e consist chiefly of sands and clays. Residual clays f rom the Ocala limestone locall y in the northern part of the county. Few of the s e, however, may be u s ed for m a nu factured products. A few somewhat sandy clays of limited e x tent occur in the eastern part of the county. One of these is fo"und at the Atlantic Coast Line station at Webs ter. It probably underlies a considerable area and is more than four feet in thickne ss. The overburden i s about three feet of sand and soil. Only a soft, porous building brick of very inferior quality can be made from this clay. It has the following physical properties: Physical Properties of the Webster Clay (Lab. No. o-75). Plasticity, judged by feel ....... . . . . Water of plasticity . . . .... . . . ...... . Pore water .... ........... ........ . Shrinkage water ............. . ... . Linear air shrinkage .......... .... . Volume air shri nkage . . ........... . Modulus of rupture, average ....... . Slaking test ................. ..... . Good. 25.90% 1.55% 24.35% 10.8 % 29. 6 % 328.5 pounds per square inch. 5 minutes. 

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A PRELIMINARY REPORT ON CLAYS OF FLORIDA 207 Fi r e tests : T LinearShr. A bsorptioiz . PorositJ. Color . Per Cent . Per Cent . Per Cent . 950C. 0 . 8 14.79 33.20 Reddish brown . 1050 0 . 8 14.80 33.60 Reddish brown. 1150 0.8 14.37 33.10 Reddish brown. 1190 0.8 14.53 . 32 . 00 Reddish brown. 1230 0.8 14.95 21.50 Reddish brown . SUWANNEE COUNTY Suwannee County is located in north Florida and is underlain by the Ocala, Chattahoochee and Alum Bluff formations . A sand-clay mantle covers most of the county and may be used for road material. Residual clays froin both the Ocala and the Chattahoochee lime stones occur locally, but none of these are for use i n burned products. Sandy clays occur comm . only in the central and eastern parts of the county . Some of these may be used for a poor grade of common brick. A r ed-mottled clay, occurring one mile north of Live Oak on the property of W. H. Lyle, was tested by the Bureau -of Standards 1914,1 and has the following physical properties : Ph1sical Properties of W . H. L1le Cla1 (Bureau of Standards , Sample No. 6). Plasticity .........•... . ........ .... Water of plasticity .•.. • • . .•........ Linear a i r shrinkage .•....... . ..... Fire tests : Temperature . L i near Shr . 950C. 1010 • 1040 1070 uoo 1130 1160 1190 1220 1250 1280 1310 Per Cent. 2 . 39 5 .68 5.89 5 . 62 Good . 40.5% 11.79% Porosity. Per Cent. 33.27 31.45 29.00 24.70 24.37 24.65 23.85 24.70 24.67 24.53 23. 96 24 .65 TAYLOR COUNTY Color . Light red. Light red. Light red . L i ght red. Dark red. Dark red . Dark red. Dark red. Dark red. Dark red. Dark red. Dark red. Taylor County lies in north Florida and borders on the Gulf of Mexico . It is underlain chiefly by the Chattahoochee formation. Some 1Sellards, E . H . , Report on Tests for Paving Brick , Florida Geol . Survey Press Bulletin No. 7, 1915. . 

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208 FLORIDA GEOLOGICAL SURVEY-I 5TH ANNUAL REPORT clays occur in . this region, but they unfitted for use in manufactured products. UNION COUNTY Union County is located in the n orthern part of the peninsula. Sandy clays are of common occurrence, but none in which the clay content is high enough for use in burned products. VOLUSIA COUNTY Volusia County is situated in the north-central part of the peninsula and lies between the St. Johns River and the Atlantic Ocean. The west ern part of the county is underlain principally by the Nashua marl. Sands, clays and marls comprise the surface formations. Some flood plain clays qccur near Lake George in the northwestern part of the county. The eastern part of the county has a heavy mantle of Pleisto cene sands. o ne very small clay deposit was for common brick long ago on the coast, two miles north of Onnond Beach. The deposit is now covered by a sand dune and only parts of the dismantled machin ery rna y be seen. A marl-pit in the south part of the city of DeLand contains an overburden of thin sedimentary clays interbedded with sands and marls. It has the following sectio .n: Section in Marl Pit, South Part of DeLand. Feet . Inches. Sand ................................................... 3 to 6 Clay, red, sandy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 6 Clay gray, sandy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 Clay, gray, jointed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 Shells . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 Clay, gray, brown . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 6 Shells ............................................. . . . . 10 Marls ........... . . .................................. . . . ? A sample of each of the two lower gray clays, which are separated by three inches of shells, was mixed in equal proportions and te sted . The overburden over these clays is sufficiently great to preclude their having any commercial importance in . themselves, but as this material 

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A PRELIMINARY REPORT ON CLAYS OF FLORIDA 209 is now removed in order to obtain the underlying marl for road purposes, this clay n1ight be of some value as a by-product . This mixture has excellent drying and working qualities, is red burning, and would be suitable for a good grade of structural materials. The shells associated with these two clays are detrimental and would necessarily have to be retnoved or very finely ground. The physical properties are : Physical Properties of DeLand City Clay (Lab. No. 0-4-8): Plasticity, judged by feel. . . . . . . . . . . Excellent. Water of plasticity................. 29 .90% Pore water . . . . . . . . . . . . . . . . . . . . . . . 6.12% Shrinkage water . . . . . . . . . . . . . . . . . . 23.78% Linear air shrinkage. . . . . . . . . . . . . . . 13.0 % Volume air shrinkage.............. 38.0 % Modulus of rupture, average........ 966.5 pounds per square inch. Slaking test . . . . . . . . . . . . . . . . . . . . . . . 30 minutes. Steel hard at cone 010. Fire tests: Temperature. Linear Slzr. Absorption. Porosity. Color. Per Cent. Per Cent. Per Cent. 950C. 1.0 11.40 27.95 Brick red. 1050 2.0 9.72 25.95 Brick red. 1150 2.0 9 . 96 25.20 Brick red. 1190 1.0 7,49 21.20 Brick red. 1230 0.5 12.51 26.75 Brick red. A sandy clay, occurring in the northwest part of the city of De Land, was formerly worked for common brick. The deposit consists of thr ee feet of sand, three feet of red-mottled clay, and three feet of a buff clay, by a sand. This clay may be used for a porous, common brick. The physical properties are: Physical Prop ertie s of Herman Brown Brick Yard Clay (Lab. No. 0-35). Plasticity, judged by feel ........... . Water of plasticity ................. . Pore water ...... ............... . . Shrinkage water ............. .... . Linear air shrinkage .............. . Volume air shrinkage ............. . Modulus of rupture, average ....... . Slaking test ...................... . Excellent. 26.70% 0.00% 26.70% 10.7 % 27.75% 306.4 pounds per square inch. 10 minutes. 

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210 FLORIDA GEOLOGICAL SURVEY-I 5TH ANNUAL REPORT Fire tests: Temperature. 950C. 1050 1150 1190 1230 1310 1430 Linear Shr. Per Cent. 1.2 1.3 1.3 1.2 1.3 1.3 1.7 A b.rorption. Per Cent. . 18.9 5 19 .78 17.30 17.42 18.22 15.20 15.58 Porosity. Per Cent. 38.00 38.50 38.30 38.50 35.75 35.00 34.80 Color . Cream . Cream Cream. Cream. Cream. Cream. Cream. A brick plant was formerly operated about one-half mile south of the station at Springs. The Volusia County Commissioners have opened a pit to obtain marl in the same deposit, one-quarter mile farther southward. The deposit consists of two feet of sand, four feet of gray, plastic clay. The clay is underlain by marl. It underlies an ex tensive area in the vicinity of DeLeon Springs . This clay may be used for a good grade of common structural materials. It has the following physical properties : Physical Properties of Polusia County Shell and Marl Clay, DeLeon Springs (Lab. No. o-70). Plasticity, judged by feel. . . . . . . . . . . Excellent. Water of plasticity............... . . 20.10% Pore water . . . . . . . . . . . . . . . . . . . . . . . 1.90% Shrinkage water . . . . . . . . . . . . . . . . . . 18.20% Linear air shrinkage. . . . . . . . . . . . . . . 8.0 % Volume air shrinkage.............. 25.7 % Modulus of rupture, average........ 532.3 pounds per square inch. Slaking test . . . . . . . . . . . . . . . . . . . . . . . 5 minutes. Fire tests: Temperature. Linear S lzr. Absorption. Porosity. Color. Per Cent . Per Cent. Per Cent. 950C. 0.5 14.69 34.50 Brick red. 1050 0.5 14.30 34.00 Brick red. 1150 1.0 14.29 32.70 Brick red. 1190 1.0 14.33 31.10 Brick red. 1230 1.5 13.09 31.80 Brick red. 1370 1.5 12.16 32.25 Brick red. The same conditions prevail a half-mile southward or1 the property of George LaFevre, except that the clay has a thickness of five feet and an overburden of only a few inches. The quality of the clay is the same. Several pits have been opened and a railway spur built to them . The clay i s n o w bein g rem o ved a s ail o v erburden in wo rkin g the n 1 arl. Another brick plant was formerly operated at Deep Creek, three miles north of DeLeon ! Springs. This deposit consists of an overburden 

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A PRELIMINARY REPORT ON CLAYS OF FLORIDA 211 of three feet of sand and / hardpan and five feet of blue, sandy, plastic clay which is underlain by marl. The clay has good working qualities and may be used for a good grade of common structural materials. Its physical properties are: Physical Properties of Deep Cruk Clay, DeLeon Spring.r (Lab. No. o-74). Plasticity, judged by feel .......... . Water of plasticity ................ . Pore water ...................... . Shrinkage water ................. . Linear air shrinkage .•..........•.. Volume air shrinkage ............. . Modulus of rupture, average ....... . Slaking test ...................... . Steel hard at cone 010. Overfires at cone 9. Fire tests: Temperature. 950C. 1050 1150 1190 1230 Linear SIJr. Per Cent . 0.7 0.7 0.7 . 0.7 1.2 Absorption. Per Cent. 12.19 12 . 80 10.39 8.26 7.82 Excellent. 24.50% 1.50% 23.00% 9.3 % 32.6 % 635.0 pounds per square inch. 5 minutes. Porosity . Per Cent. 27.80 28.20 26.00 27.65 27.00 Color. Brick red. Brick red. Brick red. Brick red . Brick red. WAKULLA COUNTY Wakulla County, in nuddle Florida, i s bordered on the south by the Gulf of Mexico and on the west by . the Ocklocknee River. While the county is underlain by the Chattahoochee, Alum Bluff and Choctaw hatchee formations, a heavy surface mantle of loose sand conceals thetn over much of the county. Nlo clays of importance are known in the county. A samply from the southwestern part of the county, submitted by S. B. Crowder to the State Geologist, was te s ted in 192 0 by the Bureau of Standards.1 The result of the test was as follows : Plasticity ......................... . Water of plasticity ................ . Linear air shrinkage .............. . Overfires at cone 10. , Fired color, dark brown. Fair. 30.0% 12.7% WALTON COUNTY Walton County is situated in west Florida, hatchee River, and extends from the Florida-Alabama boundary to lLetter from Director . U. S. Bureau of Standards to State Geologist of F'lorida, August 16th, 1920. 

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212 FLORIDA SURVEY-15TH ANNUAL REPORT the Gulf of Mexico. It is underlain by the Chattahoochee, Alum Bluff , Choctawhatchee and Pleistocene formations . The same sandy clay man tle, so . commonly present in Florida, also covers much of Walton Count y . A reddish and gray mottled clay is used at the Brick Works, at Glendale, in the production of common brick . This depo s it is more than thirty feet in thickness and underlies at leas t forty acres, and probably more, in the vicinity of Glendale. -This plant is now operated only at intervals to supply local trade. Formerly a logging railroad connected thi s place w ith DeFuniak Springs and thus afforded an outlet for the product, but the railroa d i s now abandoned . The clay is well suited for an excellent grade of common structural materials and red earthenware. Its physical properties are: Physical Properties of Glendale Clay (Lab . o -11). Plasticity, judged by feel . . . • . . . . . . . Excellent. Water of plasticity . • . . ;............ 27 .50% Pore water . . . . . . . . . . . . . . . . . . . . . . . 0.46% Shrinkage water . . . . . . . . . . . . . . . . . . 27.04% Linear air shrinkage. . . . . . . . . . . . . . . 8 . 7 % Volume air shrinkage...... ........ 29. 9 % Modulus of rupture, average........ 139. 1 pounds per square inch. Slaking test •. . . . . .... ............. Steel hard at cone 1. Overfires at cone 16. Fire tests: Temperature. Linear Shr. Absorption . Porosity. Color . Per Cent. Per Cent. Per Cent. 950C. 0.2 20.20 37.20 Light red. 1050 1.3 20.50 37.15 Light red. 1150 5.8 18.80 28.20 Light red. 1190 5 . 8 11.58 19.35 Light red. 1230 5.8 8.35 20.75 L ight red. 1310 6.3 5.30 17 .10 Light red. 1370 . 6 . 8 4.68 15.30 Light red. 1430 8.3 4.65 14.20 Light red. Mr. G. H. Murphy, who operates the Glendale Brick Works, and who was employed to manufacture the for the Allentown Consolidated in Santa Rosa County , ( s ee page 202), i s preparing to operate a brick plant on the property of R . J. Edwards in Sec. 14, Twp. 3 N., R . 18 W., three miles north of Argyle. Part of the machinery has already been installed. 

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A PRELIMINARY REPORT ON CLAYS OF FLORIDA 213 This is a flood-plain havirig a thickness of more than ten feet and a two-foot overburden of sand. The Louisville and Nashville Railroad, at Argyle, is the nearest shipping point. The clay is red-burning and is suitable for a good grade of struc tural Its physical properties are: Physical Properties of Edwards Clay, Argyle (Lab. No. o-8o). Plasticity, judged by feel. .......... . Water of plasticity ................ . Pore water ...................... . Shrinkage water ....... ........ . . . Linear air shrinkage .............. . Volume air shrinkage ............. . Modulus of rupture, average ....... . Steel hard at cone 1. Fire tests: Temperature. Linear SIJr. Absorption . Per Cent. Per Cent. 950C. 0.3 20.29 1050 1.0 20.77 1150 1.8 11.11 1190 . 7.0 9.00 1230 7.0 8.67 1310 7.0 8 .21 1370 7 . 0 6.29 1430 9.0 0.65 26 .40% 1:01% 25.39% 8.00% 27 .80% 349.7 pounds per square inch. Porosity. Color. Per Cent. 34 .35 Brick red. 36.85 Brick red. 24.75 Brick red. 21. 40 Brick red. 21.65 Brick red. 21.86 Brick red. 18.60 Brick red. 8.45 Brick red. A sandy surface clay occurs on the property of Perry L. Biddle, one n1ile south of DeFuniak Springs. It burns to a friable and porou s red-colored product and therefore is suitable . only for a common brick of inferior quality. A white, sandy, micaceous clay, containing some coarse quartz, occurs on the property of G. P. Billups in Sec. 26, T. 2 N., R. 19 W., five miles south of DeFuniak Springs on the Freeport road. The sand, mica and gravel . content of this clay renders it useless for manufacturing purposes in its present form . It is probable that the' clay would be of son1e value when washed . The nearest point is DeFuniak Springs. A black plastic clay occurs on the property of R. W. Thompson, one n1ile north of DeFuniak Springs . This stratun1 is ten feet in thick ness and is overlain by twenty feet of sand. Sand also underlies the clay strata. This is a white-burning clay. Its exceedingly heavy over burden probably prevents it from having any commercial value at the present time. 

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214 FLORIDA GEOLOGICAL SURVEY-15TH ANNUAL REPORT WASHINGTON COUNTY Washington County lies in west Florida and is bordered on the west by the Choctawhatchee River. It is underlain by the Chattahoochee, Alum Bluff, Choctawhatchee and Pleistocene formations. The only clay of any value found in the county is a flood-plain de posit ab out t w o mile s sou t h w e s t of Chipley, which depo sit is being worked b y the Hall Brick C01npany common brick. The neares t rail w ay is t w o mile s and practi c all y all of the product is s old locall y . The deposit has b e en proven on about sixty acres and probably unde rlie s a more e xtensive area. The clay stratum is about three feet in thickne s s, is overlain by six inche s of soil and underlain by sand. The raw clay is black, fairly plastic and has good working qualities. It is cream-burning at the lower temperatures and changes to gray at about cone 1. This clay is suitable in its presevt state for common structural ma terials such as face and common brick, hollow-block ware, drain tile, etc. It contains a small amount of coarse quartz sand and if this is washed out the clay may be used for stoneware, flower pots, turpentine cups, and similar articles . It has the following physical properties: Plzysical Properties of Hall Brick Company Clay (Lab. No. o-7). Plasticity, judged by feel. . . . . . . . . . . Excellent . Water of plasticity.. . . . . . . . . . . . . • . . 28.80% Pore water . . . . . . . . . . . . . . . . . . . . . . . . 1.13% Shrinkage water . . . . . . . . . . . . . • . . . . . 27.67% Linear air shrinkage. . . . . . . . . . . . . . . . 9 .00% Volume air shrinkage............... 27.55% Modulus of rupture, average .... ... . 135. 4 pounds per square inch. Slaking test . . . . . . . . • • . . . . . . . . . . . . . 20 hours. Steel hard at cone 1. Fire tests: T_ emperature. Linear Shr. Absorption . Porosity. Color. Per Cent. Per Cent. Per Cent . 950C. 2.0 21.75 30.80 Cream. 1050 2.5 20.10 30.50 Cream. 1150 5.0 11.90 26.40 Gray. 1190 6.0 9 .30 21.50 Gray. 1230 8.0 6.10 . 21.02 Gray. 1310 4.80 13.10 Gray. 1370 3.84 12.75 Gray. 1430 12.0 2.59 8.55 Gray. 

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A PRELIMINARY REPOR'"f ON CLAYS OF FLORIDA 215 Fr c. 35.-Bri ck machine, Hall Brick Company, Chip l ey, Washington County. Frc. 36. D r y in g s h e d , Hall Brick Company, C hipl ey , Washington Co un ty. 

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216 FLORIDA GEOLOGICAL SURVEY-15TH ANNUAL REPORT CHAPTER IX SEDIMENTARY KAOLIN . The Florida clay which has attracted the greatest attention, both from a commercial and a scientific point of view, is the "sedimentary kaolin" , found at a nutnber of localities in the central part of the pen insula. This clay is of interest to the ceramist and the clay operator because of its wide of uses and pecu!iar characteristics, and to the geologist because of its unique p-ccurrence, and associa tion with other materials. has already been about this unusual clay with reference to its nature, origin and geologic age without these problems being definitely solved. Its physicaJ properties and uses, however, are fairly well known. TERMINOLOGY This day has been variously known as ball-clay, . china-clay, kaolin and plastic kaolin. It is commonly marketed under the name of plastic kaolin, or china-clay. The term china-clay is used broadly to include any white-burning clay, regardless of its origin. The. term plastic kaolin is misleadingin that it" might include a residu al deposit . The term kaolin is applied to a residual white-burning clay of high toriness and usually of low plasticity and bonding strength. A ball-clay is a plastic, sedimentary clay, white-burning, or nearly so, of high re fractoriness, and usually good bonding strength. None of these terms, therefore, are entirely satisfactory, as in chemical and physical properties the Florida clay is intermediate be tween a true kaolin and a ball-clay. Its chemical composition is es:.. sentially that of washed kaqlins from other regions and its alumina content ranges from three to seven per cent higher than is the case in the typical ball-clays. The Florida clay also has a much higher plas ticity, shrinkage and bonding strength than . the true kaolin . In occur rence, composition and properties it is very similar to the white coastal plaiit clays of Georgia and South Carolina, except that the Florida clays must always be washed before being used. The term "sedimentary kaolin" seems best suited for the white Florida clay, as this term shows the relationship to a true kaolin and 

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A PRELIMINARY REPORT ON CLAYS OF FLORIDA 217 at the same time indicates the origin -of the deposits in order to differ entiate them from the typical or residual kaolins. The white-burning clays of the coastal plain of Georgia and South Carolina are likewise sedimentary kaolins. DISTR!BtUTION The sedimentary kaolin is now being mined at twq different locali ties. One of these is at in Putnam County, and the other is near Okahumpka, in Lake County. Two ,companies are actively en gaged in mining the cla:Y near and one at Edgar. The deposits of sedimentary" kaolin are confined .to the peninsular portion of the State and Sellat:"ds1 states the di$tribution of this material is co-extensive, or nearly so, with the Lake Region. Deposits have, however . ; been . found well to the west of the Lake Region in Pasco, HernaQdo, Levy, and. perhaps Citrus and Sumter countie$, each of which, except Sumter, borders on the Gulf coast. Others have been reported in the viCinity of. Live Oak in Suwannee _ County and also in Lafayette County, but nothing authentic is known about these oc currences at the present time. Sellards2 further points out that the same type of topography occurs and is probably underlain by the same for nlations between the Suwannee and Choctawhatchee rivers. The oc currence of the seditnentary kaolin in the State may or may not be de pendent upon its association with the Alum Bluff formation (Miocene). While many of the plastic kaolin occurrences are in an Alum Bluff area, there is no evidence to indicate any genetic relation between the two; in fact, many of the occurrences are entirely outside the pres ent Alum Bluff areas and are apparently in no way associated with that formation. On this basis _ , then , the probabilities of finding deposits of sedimentary kaolin between the Suwannee and Choctawhatchee rivers are On the other hand, however, if the di$tribution of this clay is related to the present topography of the Lake Region, then, as Sellards intimates, there is some likelihood of finding deposits in north and west Florida. In this connection it is interesting to note the occurrence in Sec. T. 2 N ., R. 19 five miles south of DeFuniak Springs in Walton County, of a sandy clay very closely resembling the crude lSellards, E. H., _The Clays of Florida, Journal American Ceramic Society, Vol. I, p. 313, 1918. 2Loc. cit. 

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218 FLO RIDA GEOLOGIC A L SURVEY-15TH ANNUAL REPORT FIG. 37.-General View of Edgar Plastic Kaolin Co mp a n y ' s Plant, Edgar, Putnam County. seditn e ntary kaolin. This lo catio n i s eve n wes t of the areq mentioned by Se llard s . Here the sand and mica content se ems to be higher and the average s i ze of the quartz pebb le s lar ge r than in the peninsula deposits . N o ne of thi s tnaterial was wa s hed and no chemical analyses are av ai laQle to det ermine if it is actually a sedimentary kaolin. Ri es1 ha s p o inted out that i n the n o r t hern extension of the s edi mentary kaolin region the quartz pebble s are larger than is the case farthe r south. This would be natural to expect if the original source of the material is northward. This may also account for the hi g her sand and mica content of the material in Walton Count y , if it i s the same s ub s tance. In any ca se, its genesis and occurrence i s much the s ame. The depo s it s of s edimentary kaolin are of irregular outline and extent, rarely covering more than thirty acres . Thes e individu a l de po s its are often grouped t ogether and separated only by a partition ranging from s ixty to one hundre d feet in width and compo s ed of ye llovv, sandy clay, lo ose sand or hardpa n probably in dicating former s tre am-c h anne l s no w filled w ith s urfacesa nds and s andy clays. lRies, H., Clays of the United States East of the Missi ss ippi River, U. S. Geol. Survey Prof. Paper No. 11, p. 82, 1903. 

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A PRELIMINARY REPORT ON CLAYS OF FLORIDA 219 There are isolated occurrences of the sedimentary kaolin lying thirty or more mile s from an y other known depo s its. DESCRIP'riON The deposits them s elves consist of a bed of white clay-bearing sand, which appears gray in its crude form, ranging from six to more than thirty feet in thicknes s and overlain by a deposit of loose surfacesand or soil vv-hich varies frotn six to twenty feet in thickne ss . Often where it has been e x po se d to weathering, the upper foot or so of the clay is s tained w i th ir o n oxide . The depo s it i s very frequently cro ss bedded, but as the stratification and lamination s are of the same ma terial and color, the cr oss-bedding i s often indistinct . Some of the se la yers are c o ngl om eratic and h ave a tnuch higher proportion of clay substance than the average. The cla y -be aring sand is underlain at different times by vari o u s material s, s uch as g re e n clay, litne s t o ne , flint , fuller 's earth, n1arl, o r red-streaked cla y . In son1e l o calitie s fuller's earth i s reporte d t o lie in1n1ed iatel y unde rneath th e green cla y . . _,.:.:;,_ 1--FIG. 38.-Removing overburde n. Edgar Plastic Kaolin Company , Putnam County. Photo by H. Ries. --. .. 

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220 FLORIDA GEOLOGIC A L SURVEY-I 5TH ANNUAL REPORT Frc. 39.-D ipper on dre dge boat dropping crude cla y into bin from which it is pump e d up to plant. Edgar Plastic Kaolin Company, Edgar, Putnam County. Photo by H. Ries . Frc. 40.-Trough leading to settling vat. Edgar Plastic Kaolin Co . , Edgar, Putnam County. Photo by H. Ries. 

PAGE 228

A PRELIMINARY ON CLAYS OF FLORIDA 221 GEOLOGIC AGE The age of the sedimentary kaolin is not known. Matson1 places it provisionally in the -Fliocene with a query. Ries2 iists it under the Oligocene clays, but explains its position in the Tertiary system is not known. Watkins3 says, "geo lo gically, this area belongs to the Apa lachicola group of Oligocene age." The formations in the general re gion about the sedimentary kaolin occurrences were formerly included in the Apalachicola group of Oligocene age. At present, however, the Alum Bluff formation, formerly considered a part of the Apalachi cola group, is regarded as Miocene. This does not necessarily mean that the sedimentary kaolin is of the same age. Se llards4 says: "The place of the clay-bearing formation in the geologic time-scale is difficult to determine owing to the complete absence of fossils. It overlies the Oligocene limestones . There is also some reason for believing that it lies at a stratigraphic level higher than the fuller's earth beds and hence is not older than the Miocene. However, inasmuch as no one of the later formations is found over lying this formation, it is not possible to fix its age . more definitely." The fact that the clay formation is found overlying the fuller's earth confirms the belief that it is at least younger than that stage of the Alum Bluff when the fuller's earth was deposited. ORIGIN The origin of the sedimentary kaolin has not as been satis explained . . The beds are, without doubt, sedimentary, as is indicated by the cross-bedding within the clay-bearing san .d; the fact that the various substances, such as green clay, fuller's earth, lime stone, etc., underlie sand; and by the conglomeratic texture and the presence of water-worn pebbles in the material itself. This formation is apparently everywhere separated from the underlying formations by . an unconformity . lMatson, G. C., The Clays of Florida, U. S. Geol. Survey Bull. 380, p. 353, 1909. 2Ries, H., High Grade Clavs of the United States, U. S'. Geol. Survey Buii. 708, p. 289, 1922. 3Watkins, Joel H., White-:Uurning Clays of the Southern United States, Trans. A. I. M. E., Vol. 51, p. 481, 1916. 4S'ellards , E. H . , The Clays of Florida, Journal American Ceramic Society, Vol. I, p. 318, 1918. 

PAGE 229

222 FLORIDA GEOLOGICAL SURVEY-15TH ANNUAL REPORT Moreover the present deposits of this material probably represent remnants of a formerly continuous deposit covering, at least, a large portion of central-peninsular Florida. The presence of quartz and mica indicates that the material was _ derived from the residual clays of some granitic region, probably upper Georgia. That the ultimate source ot the material was to the northward is indicated by the fCl;ct that the larger pebbles are found in the northern part of the region as is pointed out by Ries.1 Davis2 in attempting to explain the high plasticity of these clays says that they are probably flood-plain clays and are supposed to have resulted from the transportation and deposition of material from a granite area. In continuing this satne line of thought, Watkins3 says : "It is very probable, however, that this kaolin was first deposited in Cretaceous times and later eroded and transported toits present posi tion. As this portion of Florida is several hundred miles farther from the crystaUine area than the Cretaceous horizon, it is reasonable to sup pose that the particles of kaolin held in suspension for so great a dis tance would be more finely divided than those which were deposited in Cretaceous beds. This, to some degree, may account for the fact that the Florida clays are more plastic than the Cretaceous clays." A different theory was earlier _ suggested by Sellards4 when he said: "The admixture of finely divided clay, kaolinitic in nature, with the coarse sands which characterize these deposits, is difficult to acco\}nt for, except upon the hypothesis that when deposited the formation con sisted of coarse quartz and feldspar sands. The quartz being more resistant has remained but little changed, forming the coarse sand of the formation. The feldspar sands, since their deposition, have been subjected to decay, thus forming the kaolinitic clay of the present for mation." This -theory encounters serious objections. If climatic and phy siographic conditions similar to those of the present are postulated lRies, H . , The Clays of the United States East Qf the Mississippi River, U. S. Geol. Survey Prof . . Paper No. 11, p. 82, 1903. 2Davis, N. f : The Plasticity of Clay and Its Relation to Mode of Origin. Trans. A. I. M. E., Vol. 51, pp. 451-480, 1916. _ .. 3Watkins, Joel H., White-Burning Clays of the Southern States, Trans. A. I. M. E., Vol. 51, pp. 481-501, 1916 . . 4Se11ards, E. H . , The Soils of Florida, Florida Geol. Survey, Fourth A.nnual Report, p. 21, 1911. 

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i\ PRJ-:1,11\IIIN/\R Y REPOR'l' ON CLAYS OF FLORIDA 223 Frc. 41.-Filter presses, Edgar P la stic Kaolin Co., Edgar, Putnam County. for Florida and the coas tal plain region s , as i s gene rally b e lieved to have been the ca se clur i no Tertiar y times, then the f eldspa r \vould have become completely decom p os ed l ong before it could have been transported frotn the c r ysta lline area on the n o rth to the kaolin region, several hundred miles so uthward. There is no evidence to indicate that the crystallin . e areas have within l ate Tertiary times been at a much greater elevation than at present t o facilitate rapid transportation . For this h ypothes i s to be workab le, rapid transporta tion of the feldspar material wou l d be necessary in o rder to avoid decomposition before final deposition. Moreover, under Sellards' hypothesi s o ne \vou ld expect to find pebb les or fragment s of undecomposed feld spar present in the forma tion, as we ll as fra gments of o nl y partially a lter ed feld spar. None have so far been rep orted. The clay .wo uld also be present in sma ll lumps in s tead of the finel y divided s tate in which it is found. In the alteration of f e l dspar to ka o lini te free s i l ica is one of the re sulting products. If it i s a ss umed that thi s s ili ca took the fonn of quartz then it \ v ould be difficult to account for the rounded and water-\vorn conditions of the quartz grains prese nt. No othe r forn1. of s ilica, as opa l , is found in or associated w ith the clay-bearing formation. 

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224 FLORIDA GEOLOGICAL SURVEY-I 5TH ANNUAL REPORT GilP suggests -that the formation of this clay-bearing sand n1ay have occurred in the following manner: Spring floods carried quartz sand and mica to the peninsular region where it was deposited as cross bedded seditnents in lagoons or other arn1s of the sea. Then, during the seasons of less rainfall, the streams etnptied n1ilky water \vith the clay substance in suspension into the areas containing the sand. The clay substance was then deposited as a thin coating over relatively thin layers of sand. The lagoons were more or less quiet during the drier seasons, but during the periods of freshets the additional quantities of water caused conflicting currents, which assisted to some extent in reworking the deposits and disseminating the clay substances more thor oughly throughout the sand. Alternate deposition of quartz-sand and milky water with alternating seasons caused the intimate of sand and clay and the accumulation of the present thickness of it. It is not only possible, but probable, as is suggested by V{ atkins , that this material was first deposited as Cretaceous sediments near the base of the granitic area, the ultimate source in the Appalachian region, and these beds were later eroded to supply the sediments for the deposits as now known in Florida. As is also pointed out by both Watkins and Davis, this would account for the higher plasticity of the Florida clays than the present Cretaceous clays of Georgia. Conditions of sedimentation, in which coarse pebbles, varying from three-fourths of an inch to less than a pin-head, could be intin1ately mixed with mica and finely divided as this material is, and yet be so free from other substances, particularly those exerting a coloring in fluence, as iron compounds, is at first thought difficult to explain, espe cially in view of the fact. that the deposits are distributed over a rela tively large area. Rettger,2 however, points out that the deposition of this material is not necessarily very different fron1 any other sandstone. The clay-bearing sand is an unconsolidated sandstone in which the clay content ranges from twenty to forty per cent. Many sandstones have a similarly high clay content. If shoreline conditions similar to those of the present are postulated for Florida during the. time when this formation was being deposited, which was probably Pliocene, with large arms of the sea, relatively shal-lGill, A. C., Oral Communication. 2Rettger, R. E., Oral Communication. 

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A PRELIMINARY REPORT ON CLA YS OF FLORIDA 225 . . . FIG. 42 .-Plant of Florida China Clay Co., near Okahumpka, Lake County. FIG. 43.-Removal of overburden by h ydraulicking . Florida China Clay Company, Lake County. low and more or l ess connected and largely land-locked , a s i s now illu strated by the nun1erous bays and sounds indenting the Florida coast line, then it is easy to conceive of a n1ore or less continuous qeposit of this sedimentary kaolin being formed around the . border of the penin su la as it existed at that titne. This formation has since been largely re-

PAGE 233

226 FLORIDA GEOLOGICAL SURVEY-I 5TH ANNUAL REPORT moved by erosion, so that the deposits known at present are merely remnants. In this connection it is to be noted that the white Cretaceous clays of Georgia and South Carolina are relatively free fr01n sand and peb bles, and, with one or two exceptions, n1ay be u sed without first bein g washed. Their properties are sin1ilar to the sedimentary kaolin of Florida, except that the Florida clay has hi gher plasticity. The immediate source of the material, i. e., clay and sand, composing the deposits in Florida, i s not easy to explain. If it is assumed that the clay was derived from the white Cretaceous cla ys of Georgia, then another source for the quartz-sand n1ust be sought and its mixture with the clay accounted for. The source of the Florida sedimentary kaolin, its transportation, geologic age, relation to other s ediments, terrestrial and s hore-line c on ditions, distribution and deposition, are problen1s as yet far from being !)Ol ved. HISTORY AND DEVELOPMENT The Florida sedimentary kaolin was discovered in 18901 in mining phosphates, and samples were sent to Mr. C. S. Edgar at Trenton, N. J. As early as 18 75, Mr. Edgar had heard rumors of kaolin deposits in Florida, but, upon going there, was unable to find any. In 1892, Mr. Edgar began mining this clay at Edgar under the name of the Edgar Plastic I<:aolin Con1pany. This con1pany is still operating at that place. In 1900 the International I<:aolin Company began mining clay in the same formation at There are at present three companies working deposits of sedimentary kaolin: The Edgar Plastic l(aolin Company, at Edgar, in Putnam County; The Lake County Cla y Con1pany, and the Florida China Clay Company, both near Okahumpka, in Lake County. PROPERTIES The sedimentary kaolin in it s crude form con sists of sixty to seventy five per cent quartz-sand and twenty-five to forty per cent clay. The average i s probably about sixty-five per cent sand. This natural n1ixture i s washed, thus separating the clay from the sand, and a part, at le ast, of the mica. The washed product, however, probably does not represen t lRies-, H., and Leighton, H., of the Clay Working Industry in the United States, p . 78, 1909. 

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A PRELIMINARY REPOR . T ON CLAYS OF FLORIDA 227 much over fifteen per cent of the material excavated. A slight amount of a very fine sand and some mica remains in the washed clay, but the quantity is not sufficient to injure it s usefulness, except for some grades of paper-clay. The was hed product at each of the three plants engaged in mining this clay varies little in its properties and uses. It is very plastic, white burning, refractory, and has mediun1 transverse and bonding strength. FIG. 44.-View of dredge boat used in mining sedimentary kaolin, Florida China Clay Co., near Lake County. Frc. 45. N ear view of dipper on dredge boCJt. Refuse sand in background. Florida China Clay Company, Okahumpka, Lake County. I . l 

PAGE 235

228 FLORIDA GEOLOGICAL SURVEY-I 5TH ANNUAL REPORT It i s n ot, h oweve r , a t ypica l b o n d cla y . It canno t be u sed a l o n e, a s it lia s a hi g h shrinkage and deve l o p s mall cracks in firin g . Frc. 46.-Entrance t o sa nd traps, Florid a C hin a C l a y Co., Okahumpka, Lake County. Frc. 47.-Settling troughs, F l o rid a C hin a C l ay Co., Okahumpka, Lake County . 

PAGE 236

A PRELIMIN ARY R EPORT ON CLAY S OF FLORIDA 2 2 9 A sample of the washed clay from the Edgar Plastic Kaolin Com pany's Plant at Edgar had the following physical properties: Physical Properties of Edgar Plastic Kaolin (Lab. No. o-57). Plasticity, judged by feel .......... . Water of plasticity ......... ....... . Pore water ...... . ................ . Shrinkage water ............ : .... . Linear air shrinkage ......... ..... . Volume air shrinkage ........ ..... . Modulus of rupture, average ....... . Slaking test •...................... Steel hard. at cone 1. Fire tests: Temperature . Linear Shr. A bso'rption . Per Cent. Per Cent. 950C. 5.0 29.49 1050 5.2 29. 46 1150 6 . 0 20.32 1190 7.5 21.45 1230 12. 0 ' 13.06 1310 12.0 14.30 1370 12.5 1430 13. 0 7.07 Excellent. 34.65% 0.21% 34.44% 10.0 % 27.5 % 169 . 1 pounds per square inch . 5 minutes. Porosity. Color. Per Cent. 45.75 White. 46.60 White. 37.80 White. 37.60 White. 27.50 30.20 White. 16.80 White. White. A sample of the washed clay from . the Lake County Clay , Company' s plant, near Okahumpka, had the following physical properties: Physical Properties of Lake County Clay Company Sedimentary Kaolin (Lab. No. o-84). PlastiCity, judged by feel .......•... Water of plasticity ..... ........... . Pore water .................. .... . . Shrinkage water ................. . Linear air shrinkage .............. . Volume air shrinkage .... ......... . of rupture, average ....... . Slaking test •...................... Steel hard at cone 3 . Fire tests: Temperature. Linear Shr. Absorption. Per C e nt. Per Cent. 950C. 3.5 34.61 1050 4 . 5 30.79 1150 5.4 23.62 1190 10.0 23.60 1230 10. 0 16.09 1310 14 . 5 14.74 1370 17.0 6.38 1430 18. 0 5.14 Excellent. 31.85% 0.42% 31.43% 8 .0% 22.0% 136.3 pounds per square inch. 3 minutes. Porosity. Color. Per Cent. 49.50 White. 47.20 White. 41.20 White. 34.75 White. 33.50 White. 30.75 White. 16. 42 White. 12.40 White. 

PAGE 237

230 FLORIDA GEOLOGICAL SURVEY-15TH ANNUAL REPORT A sample of the washed clay from the Florida China-Clay Corporation's plant, near O . kahumpka, had the following physical properties: Physical Properties of the Florida China Clay Corporation's Sedimentary Kaolin (Lab; No. o-83). Plasticity, judged by feel. . . . . . . . . . . Excellent. Water of plasticity................. 34.65% Pore water . . . . . . . . . . . . . . . . . . . . . . . . 0.59% Shrinkage water . . . . . . . . . . . . . . . . . . . . 34. 56% Linear air shrinkage ..... . . . . . . . . . . 9.5 % Volume air shrinkage.............. 25.8 % Modulus of rupture, average........ 201.0 pounds per square inch. Slaking test . . . . . . . . . . . . . . . . . . . . . . . 3 minutes. Steel hard at cone 1. Fire tests: Temperature. Linear Shr. Absorption. Porosity . Color. Per Cent . Per Cent. Per Cent. 950C. 4 . 5 34.16 42.20 White. 1050 5.5 27.08 45.75 White. 1150 6.5 16.12 32.50 White. 1190 12.5 6.78 16.10 White. 1230 13.5 4.94 12.30 White. 1310 15.5 4.86 12.60 White. 1370 16.0 1.60 6.65 White. 1430 17.5 1.37 4.38 Light gray. A sample of the washed clay from one of the mines near Oka humpka was tested in the laboratory of the Bureau of Mines1 at Columbus, Ohio. It had the following physical properties: ' General Physical Tests of Washed Clay from Okahumpka. Workability . . . . . . . . . . . . . . . . . . . . . .. Very plastic; molds well. Water of plasticity. . . . . . . . . . . . . . . . . 49.78% Volume air shrinkage. . . . . . . . . . . . . . 32.15% Linear air shrinkage, calculated. . . . 12.20% Modulus of rupture, average........ 181.00 pounds per square inch. Deformation temperature, cone 31 pi us. Steel hard at cone 3. Develops small cracks in firing. Fire tests: Temperature . Linear Shr. Absorption. Porosity. Color. Per Cent. Per Cent. Per Cent. 190C. 12.1 32.10 28.30 White. 1250 12.5 38.11 27.05 Faint cream white. 1310 14.4 37.33 23.41 Faint cream white. 1370 18.7 46.30 7.40 Cream. 1410 20.3 49.40 2.20 Buff . 1High Grade Clays of the Eastern United States, U. S. Geol. Survey Bull. No. 708, p. 291, 1922. 

PAGE 238

A PRELIMINARY REPORT ON CLAYS OF FLORIDA 231 ' FIG. 48.-Settling vat, Florida China Clay Company, Okahumpka, Lake County. 49.-Settling vat partially filled, Florida China Clay Company, Okahumpka, Lake County. The following analyses of the sedimentary kaolin indicate its chemi cal properties : Chemical Analysis of Washed Clay from Palatlaka!Ja 'River.! Silica (Si02) ....................... ......... . Alumina (AI20a) ....................... ..... ... , . Ferric Oxide (Fe20s) ........................................ . Magnesia (MgO) ..... ...................................... . Water (H20) .......... ..................................... . Sulphur Trioxide ............................................ . . . Total ................................................... . 46.11 39.50 0.35 0.13 13.78 , 0.07 99.94 lU. S. Geol. Survey Seventeenth Annual Report. Part III Cont'd, p. 837, 1896. 

PAGE 239

232 FLORIDA GEOLOGICAL SURVEY-I 5TH ANNUAL REPORT Frc. 50.-Empty settling vat. Florida C hina Clay Compan y , Okahumpka, L ake County. Ch emical Analysis of Washed Cla y from Edgar. C. Lange1lbeck} Analy st . ! S ilica ( Si02) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 5.39 Alumina (Al 203) ..................... ........... . . . . . . . . . . . . . 39.19 F erric O x ide (Fe2 0 3) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.45 Lime ( CaO) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0 . 5 1 Magnesia ( M g O ) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.29 A l kali es (Na20, K20) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.83 Water ( H 2 0 ) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 4.0 1 Total . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 00.67 MINERALOGY Somers2 studi ed s ample s of the Florida s edimentary kao l in s . micro sc opicall y and found kaolini te t o be abundant, h yd romica, abundant; and a few grains of rutil e , chlorite, and zircon to be present. He reports that s illimanite was developed in one of the test piece s fired a t 115q o C. whe re the conditions h a ppened to be favorable for its deve l op ment. He be l ieve s it to have b e en formed from the large flakes of kaolinite or low-grade h ydromi ca. USES The Florida se dimentary kaolin is used a lmost excl u sive l y in the white-ware indu strie::;. Its principa l u s es are in making pottery, dec ora tive tile, spark plugs, and e lec t ric porce l ai n. !Ch emistry of Pottery, p. 1 00. 2 Somers; R. E., Micros copic Study of C l ays i ncl ud e d in U. S . Geol. Survey, B u ll. 708, p . 292, 1922 . 

PAGE 240

A PRELIMINARY REPORT ON CLAYS OF FLORIDA FrG. 51.-Sluice :{or returning water from filter presses to clay pit. Florida China Clay Com pany, Okahumpka, Lake County. 233 The greater part of the output is shipped to the pottery centers in New Jer-sey, New York, Ohio, and Shipments are also made to other eastern states, to sotne of the Mississip f ; Valley states, and to the Pacific Coast states . One of the small potteries ' in Florida was experimentin g with mix tures of the sedin1enta ry kaolin and other clay s during the su i:' rner of 1922. The results at that time were sa ti sfactory. METHODS OF MINING The overburden is removed at Edgar and at the Lake County Clay Company's plant, near Okahumpka, by a steam shovel. At the Florida 

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234 FLORIDA GEOLOGICAL SURVEY-I 5TH ANNUAL REPORT China Clay Corporation's plant, also near Okahumpka, the overburden is removed by hydraulic process . The method of. mining this clay is very different from any com nlonly employed in clay-mining. Owing to the slight topographic relief of the region and the proximity of the ground water-table to the surface, ordinary open-cut methods would be unsucce ss ful , and consequent ly dredging is re so rted to. After the overburden is ren1oved, a pit is dug into the deposit of sand-bearing clay in which, after it is filled with water, a dredge is floated . Tpe clay is then dug by dredging and forced through a pipe to a series of three "sand traps,'' where the greater part of the sand is eliminated. The clay-bearing wafer then passes through a series of troughs, where it is continuously agitated, to cause the clay substance to remain in suspension and the impurities, which usually have a higher specific gravity, to settle out. Fr:om this troughing the clay-bearing water passes into settling vats and the water is later pumped off. The clay is then tthrough filter-presses, w'here the excess water is pressed out . The resulting cakes of damp clay are dried in either steam or air-heated drying sheds, and, when dry, are ready for shipment. From the time the clay is first dredged until it leaves the presses, all water extracted from it, and which t:lecessarily carries some clay, is conducted back to the pit . Some . clay" is lost, however, in the sand-traps and is carried out with the waste sand. The sand washed from the clay is used to some extent in concrete construction. It has been suggested that this sand could be used for glass manufacture, but so far as is known, no practical tests have been made to. determine its suitability for this usage. • DISTRIBUTION BY COUNTIES 1"' ... / Occurrences cj/sedimentary kaolin have been noted or reported in the following _; 6tnties: . • Alach1 p County-A well drilled at the gin in Hawthorne, near the easterr r 156rder of the county, is reported by W. S. Moore, of that place, !_o the clay-bearing sand at a depth of twelve feet. The thickness of the deposit it not known. This place is located only about eight miles w est of Edgar . . As occurrences of the sedimentary kaolin are known west and southwest of Edgar, similar deposits in the adjoin ing portions of Alachua County are not at all improbable. 

PAGE 242

A REPORT ON FLORIDA 235 Sedimentary kaolin also occurs two miles south of Fairbanks, on Hatchett Creek. The overburden here is less than two feet. The thick ness and extent of the deposit and its relation ' to a nearby gray clay was not determined. Citr us, Clay and DeSoto CountiesSedimentary kaolin has been reported . to occur four miles east of Inverness, and seven miles west of Floral City, in Citrus County, in the region Brooklyn and Lake Geneva, in Clay County, and in the vicinity of Arcadia, in De Soto County. These occurrences, however, were not verified . H ernando. County-Sedimentary kaolin was noted eight miles south of Brooksville on the BrooksvilleDade City road. The deposit here is approximately twenty feet thick and is underlain by a bluish-gray jointed clay. The overburden is less than three feet. This formation is also exposed in an abandoned phosphate mine, ten miles east of Brooksville and three miles west of Rital. Here there is three feet of sand as overburden and twenty feet of the clay-bearing sand exposed. Water in the bottom of the pit concealed the lower part of the formation, so its exact thickness is unknown. The relation of the sedimentary kaolin to the hard-rock phosphate was not worked out in detail. Highlands C ounty-Sellards and Gunter1 report "kaolin" in this county, but do not give specific locations. Sedimentary kaolin is no doubt the material referred to. As stratigraphic and physiographic conditions are essentially identical with those in Polk, Lake, and Putnam counties, it is not at that occurrences of this material should be found in Highlands County. La._ke County-Lake County is one of the principal producers of sedimentary kaolin in Florida. Numerous deposits are known in the south-central part of the county, south of Lake Harris, and along the Palatlakaha River for a di. stance of ten or twelve miles . Two plants are actively engaged in mining this material about two miles east of Okahumpka, near . the junction of the Palatlakaha River and Lake Harris. One of these is the Florida China Clay Corporation and the other is the Lake County Clay Company. The plants are about one mile apart and both are located on spurs of the Atlantic Coast Line. !Sellards, E. H., and Gunter, Herman, Petroleum Possibilities of Florida, Flor ida Geol. Survey Fourteenth Annual Report, p. 107, 1922. 

PAGE 243

236 . FLORIDA GEOLOGICAL SURVEY-I 5TH ANNUAL REPORT The Florida China Clay Corporation's mine was formerly known as the Old Richmond and is located in Sec. 12, T. 20 S., R. 24 E . The Lake County Clay Cotnpany's plant is located in Sec. 13, T . 20 S . , R. 24 E. It is operated by the san1e company that owns and oper ates the plant at Edgar in Putnam County. The mine was formerly known as the Florida Clay Con1pany Mine and has been in . operation about thirty years. The clay in this general regio!l occurs in deposits of irregular thickness and outline and are separated by partitions of yellowish sand, probably old erosion channels, which run in various directions. N umer ous exposures of the sand may be seen along the Palat lakaha and on the south shore of Lake Harris. The following typical sections indicate the range in thickness of overburden, clay a11:d the n1aterial beneath the clay-bearing formation. These sections are taken from records of borings on the property of the two companies operating here: Sedimentary Kao.lin Section.r, near Okahumpka. 1. Sand, yellow ish (overburden) .............. .................... . Clay, red, sandy . ............................ ................... . s edimeQtary kaolin sand ......................................... . Blue clay ...................................................... . 2. Sand, surface ............................ ..................... : . Sedimentary kaolin sand ......................................... . Limestone ............ ................ ........................... . 3. Sand, surface ................................................... . Sedimentary kaolin sand ....................................... .. . Flint ....................... ...................................... . 4. Sand, surface ....................... ............................ . Sedimentary kaolin sand ........................................ .. . Mar I . ................................... . ..................... . 5. Sand, surface ............................... ...... : ............. . Sedimentary kaolin sand ........................................ . 6. Sand, surface . ............... ....... . ............................ . Sedimentary kaolin sand ....................................... . . Green clay .............. : ...................................... . Feet. 6 3 30 ? 11 27 ? 10 30 . . ? 6 25 . ? 4 14 6 " 19 ? 

PAGE 244

A PHJ!LIMIN .t\RY RgPOR'l' ON CLAYS OI" FLORIDA. FI G . 52.-Motor u se d in loading cars . Florida C hina C l a y Company , Okahumpka, Lake County. FI G . 53.-Loading cars . Flor.ida China C la y Company, Okahumpka, Lake County. 237 As may be s een from the s e s ection s, the materials underlying the s e di n1entary k aoli n are variable. Fuller s earth was encou n tered in so me of the b o rin gs . The n1axin1un1 thickne ss o f cla ybe a rin g sand f ound in thi s region was 32 feet. Seditnentary kao lin is exposed on the so uth s ide of Lak e Harris, o n the property of R. F . l ( l e is er, in Sec . 22, T. 20 s . , R. 25 E. A . 

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238 FLORIDA GEOLOGICAL SURVEY-15TH ANNUAL REPORT four-foot exposure of the clay-bearing sand may be seen above the level of the lake . The overburden is three feet of soil and the clay is thirty feet in thickness. This deposit is three miles east of the Lake County Clay Company's plant and one-half mile east of Yalaha . Levy County-An occurrence of sedimentary kaolin was noted a road-clay pit in the northwe s t part of Bronson, about two hundred yards north of the Seaboard Air Line Railway station. About six feet of the clay-beari!lg fonnation was exposed, the depth and extent of the deposit was not determit?-ed . The overburden was about three feet. Marion County-Occurrences of sedimentary kaolin have found in both the extreme southeast corner of the county and in an area in the northwestern quarter of the county. A water weU, dug on the property of Captain E. E. Greer, Sec. 32, T. 17 S., R. 26 E . , in the southeastern part of the county, w ent through twelve feet of soil and surface sand, then through thirteen feet of sedimentary kaolin. The well stopped in the clay-bearing sand, hence its thickness is not known. Another deposit, also in Sec. 32, T . 17 S., R. 26 E ., was found on property of Harry L . . . Collins, about three-quarters of a n1ile northwest of the Greer occurrences. The overburden here consisted of feet of loo . se surface sand and seven feet of red sandy clay (sand clay road material). Ten feet of the clay-bearing sand was exposed immediately below the red sandy clay. Its exact thickness and extent was not determined. In the extreme southeast corner of the county and extending into Lake County, near Altoona, is another deposit in which fifteen . feet of the clay-bearing sand is exposed . It is overlain by five feet of sand. The thickness and extent of the clay formation was not determined. This deposit has been worked tor road material and contains more numerous coarse gravel, or conglomeratic layers, than the average. Occurrences of the clay-bearing formation was noted in the north western part of the county near Friendship School, ten miles northwe s t of Ocala, and in two exposures three miles ' northwest of Emathla, on the Tampa and Jacksonville Railroad. The thickness and extent of these deposits was not determined. 

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A PRELIMINARY REPOR'f ON CLAYS OF FLORIDA 239 : . :l -. FIG. 54.-Dredge Boat (in l eft background), sl uiceways and sand traps (foreground) . Lake County C l ay Company, Okahumpka, Lake County . FIG. 55.-General view of drying sheds, wareh o us es and loadin g d ocks. Lake County Clay Company, Okahumpka, Lake County. I . I 

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240 FLORIDA GEOLOGICAL SURVEY-15TH ANNUAL REPORT A six-foot stratum of ' the sedimentary kaolin-bearing sand, over lain by three feet of soil, is exposed in a well at the home of B. . S . Quarterman, Sec. 34, T. 13 S., R . 20 W. The clay formation is underlain by fuller's earth, which is reported to be twenty-three feet in thickness. Pasco County-Exposures of the sedimentary kaolin sand were noted arout:td the border of Mirror Lake, a few miles northwest of Dade City. The thickness and extent of this deposit was not de termined. The pl . astic kaolin also appears on the property of Jas. Lampson, one-half mile east of the Atlantic Coast Line Railroad and three miles southeast of Dade City. This deposit is overlain by about three feet of soil. .The extent of this deposit is to be more than ten acres. Another occurrence of this clay is on the property of J. H. Klecker, one mile northwest of San Antonio, in Sec. 34, T. 24 S., R. 20 E. A boring indicated three feet of surface sand, six feet of red clay sand, and three feet plus of the white clay-bearing sand. The full thickn . ess and extent of this deposit was not determined. Polk Cottnty-The s edimentary kaolin occurs in numerous places in Polk County in the vicinity of Bartow Junction (Lake Alfred) and Winter Haven. Putn011'n County-This county is one of the principal producers of sedimentary kaolin in Florida, a s shown on preceding pages.Numerous occurrences known in the region about Edgar, Johnson and Mc Meekin. The Edgar Plastic Kaolin Company operates one mine at Edgar. A generalized section at this locality is: Overburden . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 to 20 feet Clay.:bearing sand . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 to 30 feet The clay is underlain places by a red-streaked clay, two feet in thickness, in places by a limestone and in other places by a green clay . Fuller's earth is reported to underlie the green day in places. The Foster Kaolin Company's mine, now abandoned, is located at Johnson. Here the overburden ranges from twelve to twenty feet, and the clay formation is approximately thirty feet in thickness. Sedimentary kaolin has also been found on the Monroe : property in Sec . 32, T. 10 S., R . 23 E. This . is only a short distance southeast of McMeekin and southwest of Johnson. 

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A PRELIMINARY REPORT ON CLAYS OF FLORIDA 241 Suwannee County-Sedimentary kaolin has been reported in the yicinity of Houston and also southwest of Live Oak, but . these occurrences were not confirmed. Walton County-The white sand mentioned on page 213, is in Walton County, five nules soutlh of DeFuniak Springs in Sec. 26, T. 2 N., R. 19 W., on the property of G. P. Billups. This depqsit occurs in a small gully washed into an old field near a small stream. The material contains more mica and larger quartzose pebbles than the occurrences of typical sedimentary kaolin, and it is not defi nitely known that this material is the same. 

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242 FLORIDA GEOLOGICAL SURVEY-I 5TH ANNUAL REPORT CHAPTER X DEVELOPMENT AND POSSIBILITIES OF THE CLAY INDUSTRY IN FLORIDA EARLY HISTORY Common building bricks have been produced in Florida since the early days of its history. Ruins of the old English and Spanish settle ments in vicinity of Pensacola indicate that brick were used to a large extent in the construction of dams, foundations, fireplaces, etc., in fue eighteenth century. The ver y earliest enduring structure s, both at St. Augustine and at Pensacola 1 were of stone, but later buildings were of brick. While it is not known that these brick were made from local clays, it is curious to note that brick plants are now operated in close proximity to some of. these old Spanish and English landmarks and that clay suitable for common brick is found underlying many of them. It seems improbable that the brick used here would have been imported . The exact date when brick were first used is not recorded. In 1766, clay from Pensacola was shipped to Josiah Wedgewood's pottery in England, for experimental purposes2 • Williams, writing in 1827, states that both brick and fire-brick were manufactured in West Florida and shipped to New Orleans.3 During t'he nineteenth century, both before and after the Civil War, the Anglo. Saxon settlers, then blazing the trail for the permanent settlement of the Florida of today, operated small brick-yards to supply their immediate needs . Many of these crude which are now abandoned, may be found throughout the central, northern and western portions of the State. Fort Jefferson, on the Dry Tortugas, in the Gulf of Mexico, was built in 1860 of brick tnade on Escan1bia Bay.4 RECENT HISTORY In the last three or four . decades, eighteen or twenty plants, manu facturing structural materials, have been iQ. operation more or less con tinuously, and during this time the rank of Florida, as determined by lGonzalez, Mrs. S. J., Pensacola, Its Early History, Quarterly of the Florida Historical Society, p."10, April, 1909. 2Meteyard, Eliza, Life of Josiah Wedgewood, Vol. I, p. 471, 1865. 3WiJiiams, John Lee, 1\ View of West Florida, p. 69, 1827. 4Crary, J. W., Sr., Brickmaking and Burning, pp. 14 and 35, 1890. 

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A PRELIMINARY REPORT ON CLAYS OF FLORIDA 243 the value of its clay products, has ranged between thirty-seyenth and fortieth as a brick-producing State. Common brick has been by far the item of production, but hollow block, drain tile and face brick . have also been produced to _ some extent. The development of. the common-brick industry has made relative ly little progress within the past thirty or forty years and has . fallen far short of keeping pace with the constantly growing demand for materials. The reasons for this conditi<?n are " varied, and will be treated in subsequent paragraphs. STATUS Seventeen plants are at present in the production of com mon brick. Two of these plants are located in the northeastern part of the State, four in the north-central part of the peninsula, and the re maining eleven are situated in west Florida. That portion of the State which has the greatest demand for brick and other structural materials has only about one-third of the producers within reach . Five ofthe common.:brick producers also manufacture face brick, two of them also produce hollow block, and one produces drain tile . For these higher-grade products more thorough preparation of the raw clay is made and mqre careful treatment during the of manufacture is accorded it. In each case, however, the same raw materials are used as for the common brick. No stoneware is now being . produced in Florida. A pot ! ery manu facturing jugs, jars, crocks, and articles , was formerly operated at Pensacola . One brick plant, Barrineau Bros . , at Quintette, is equipped for the manufacture of turpentine cups . Three small potteries are being operated in the State and these are engaged .chiefly in the production of ornamental articles , such as candlesticks, vase s , urns, jardinieres, book-ends, and the like. These pieces are often made of clays of several shades, so as to bring out a pleasing contrast of colors. Such wares are not glazed and are burned only sufficiently hard to enable them to withstand ordi nary handling. Vitrification is never reached. Some of the products of these potteries are made of blends of several clays which are thor oughly mixed and to which a glaze is frequently applied . Many of . . the pieces, both those made from natural clays and those made from 

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244 FLORIDA GEOLOGICAL SURVEY-I 5TH ANNUAL pottery mixtures, or. blends, are , after firing, painted and decorated by hand. Clay products of this type find a ready local market among the tourists in the winter resorts of. the State. The Orlando P . ottery is located two miles northwest of Orlando on the Apopka Roaq . This company, which has only about two years, is equipped to carry on an extensive trade in orna mental pottery, curios, etc. The operation up to this time may be re . garded as largeiy experimental ' in determining the best biscuit and glaze formulre as well as the most satisfactory treatment to be accorded the materials and' the most expeditious methods of handling the wares. The materials are washed, mixed and tempered by hand . and molding is ' done by throwing and by casting. Burning is done in one large cir cular up-draft kiln and two small down-draft kilns. From fifteen to twenty persons, including the decorators, are employed. Some of the ware is placed on the market in an unglazed condition and the re mainder is glazed and then decorated by hand. Most of the output is sold in Orlando, but shipments are also made 'to south and east Florida. Feldspar and flint are shipped in from northern markets, and, in the past, clays from other states have been used. Some local clays, however, have since been found which give satisfactory results in cer tain blends and these have displaced the northern clays to some extent. The Florida sedimentary kaolin been successfully tried 1n some of the mixtures. Saggers are purc . hased from northern and wad clay is also procured in the North. Seger cones are used . to indicate the of firing, which is ordinarily completed at cone 06. The Florida located at 2430 Euclid Avenue, Peters burg, produces the "Kohler ' Ware!', marketed in numerous places in south Florida. This consists of vases, jars, etc., in attractiye and decorations prepared primarily for tourist trade. As many as four or five clays are at times used in such a way as to give the ware a appearance. These clays are of different colors and are not intimately mixed as a blend but used as small stringers so that a series of colors show in the finished products : A glaze is applied to the of the ware. The clays are washed and tempered by hand. Molding is done entirely by throwing on a potter's wheel. The H. A. Graack & Son Art Pottery, located in . Bradentown, uses chiefly a clay dredged from the Manatee River, which first al lowed to weather for a time, then washed and prepared by hand. Mold-

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A PRELIMINARY REPORT ON CLAYS OF FLORIDA 245 ing is done by throwing . No blends are used. The product, which is sold locally, includes hand-decorated vases, candle-sticks, curios, etc. The ware is burned in a sn1all up-dr.aft kiln . ' With the exception of sedimentary kaolin and the fuller's earth, no raw clays are mined in Florida for shipment to points out side the State. For a discussion of the kaolin, see Chapter IX. PRESENT TENDENCIES General Developn'Lint a n d Expcms ion in Florida-The growth and development of the industries of Florida during the past few years has been phenomenal. This expan s ion is perceptible in every industry in the State and is closely related tC? the general development and improvement which has been taking place in all the Southern States . The magnitude of Florida 's industries may be determined from the following table of production in the year 1920: Agriculture ............. .............................. $150,139 , 749.00 Minerals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20,000,000.00 Forest Products . . . . . . . . . . • . . . • • . . . . . . . . . . . . . . . . . . . . • • . . 25,000,000.00 Fisheries . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20,000,000.00 Manufacturing . • . . . . . . . . . . • . . . . . . . . • . . . . . . . . . . • . . . . . . • 150,000,000.00 Of these industries, agricultural , including horticultur-al pursuits, are of chief importance, and are the ones most likely to continue to ex pand. Of 35,111,040 acres of land in the State and of which, it is claimed, approximately 85 per cent is capable of cultivation, only 17.2 per cent is now in farms and only 6.5 per cent is classed as improved land. Not all of thi s is actually cultivated. The mineral production consists chiefly of phosphates, fuller's earth, lime and sedimentary kaolin, with a few other products playing a minor part. The mineral indu stry of the State is not likely to greatly increase, unless now unkn<?wn products are discovered, but will prob ably remain at about the same point for some time in the future as in the past ten years. While Florida is not regarded as a manufacturing State, the value of its manufactured products at present equals the value of the agri cultural products. The manufacturing in the State are ca pable of, and likely to be, greatly increased in the coming years. There is a decided tendency for many manufacturing concerns to move to 

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246 FLORIDA GEOLOGICAL SURVEY-I 5TH ANNUAL REPORT . -the Southern .States, where a more favorable climate and lower living costs prevail. . Parts of Florida have become widely kn9wn as winter resorts. This is particularly true of the Atlantic coast, the southern two .. thirds of the peninsula, and t?e Gulf coast . This has given rise in the tourist centers to a development peculiarly adapted .to the needs of winter visi tors, and has for extraordinary amount of building in this part of the State. In 1921, there were 5,312 miles of railway within the State , which amply serves the regions already developed, and in which development will continue for some time; Water transportation is also highly de veloped and _ is carried on inland by rivers, lakes and canals. Interstate and foreign marine commerce is an . item .of considerable magnitude, which is handled through three chief ports (Jacksonville, Tampa, and Pensacola) and numerous smaller ones. OF STRUCTURAL MATERIALS Within the last half-century the production of common brick and tile in Florida has not supplied the demand . for these materials. Geor gia and Alabama producers have been called on to supply the shortage, which has resulted in Florida becoming one of the principal markets for the products from these The increase in freight rates, in addition to the enormous development in south Florida, has, within the last decade, caused an earnest inquiry into the possibilities of developing a local supply of structural materials adequate to meet ' this growing demand or for finding substitutes . The three producers in the extreme western of the State ( Escambia County) have, on the other hand, marketed much of their output in neighboring states, even supplying wants as far away as New Orleans. It is to be noted, however, that the shipping distance by rail from Pensacola to South Florida is greater than from the Piedmont section of Georgia, thus making it cheaper to use Georgia products than those from West Florida. Shipment by water from Pensacola would . mean hauling the brick several additional times, thus making it little, if any, cheaper than rail transportation. It is most expedient, for Georgia brick to be used in peninsular Florida, when local supplies are inadequate or of unsuitable quality, in preference to 

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A PRELIMINARY REPORT ON CLAYS OF FLORIDA 247 the products from western Florida ; and on: t he other hand, the Escambia County producers can best dis pose of their wares in West Florida and ad joining portions of Alabama and Mississippi. Paving prick; the highest face brick sewer pipe are not produced in and, is known at the present time, there are no clays within the State a.dapted to the manufacture of these products. Face brick of good quality can be produced in many places, but the best grades, suited for certain types of work, cannot be satis factorily produced. For paving brick, sewer-pipe, and certain grades of face brick, therefore, Florida will be dependent upon outside supplies. SUBSTITUTES FOR CLAY PRODUCTS Numerous substitutes for clay-building products have been used with varying . degrees of success and, without doubt, some of them will continue to be extensively used. Reinforced concrete, for example, has proved very satisfactory in Florida as in practically all of the other states, and much of the structural work of the future will be of this material. At present, Portland cement is not produced in Florida, and again Georgia and Alabama products, or those from other states, must be imported with very high freight rates to supply local needs; moreover, clean, sharp sand gravel for concrete work is difficult to obtain in south Florida, where the greatest construction work is being CC\,rried on. The lime industry in Florida is an important one and has given rise to the production of sand-lime brick. These are artificial brick, made of sand and quicklime. Florida ranks third in the manufacture of sand-lime brick. These brick have the same dimensions as common brick, and are used in structural work in the same manner. The use of brick has proven successful, and will doubtless continue be a common substitute for brick. Florida has no good building stone. Some of the soft limestones in west Florida and the coquina rock well as the oolitic limestone oc curring along the east coa s t, have been successfully used to some extent for structural materials. An artificial building stone , particularly for ornamental work, columns, arches, keystones, sills, etc., is made of crushed Ocala lime stone, coquina, or loose shells, with sand and lime. This makes a very 

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248 GEOLOGICAL SURVEY-I 5TH ANNUAL REPORT attractive product and is used in lietJ of hard limestone, sandstone, or crystalline rocks that would have to be imported. Many gypsum products, princip ' aliy hollow blocks, h(;lve also been widely used for inside walls, fireproofing, and similar work, where the strength of the material is not of prime importance and where there is no exposure to atmospheric conditions. All of the above-mentioned forms of building material have been used in lieu of clay products. ATTITUDE OF SOME CONTRACTORS AND BUILDERS TOWARD FLORIDA PRODUCTS In the past, the average common and face brick supplied to Florida markets by Georgia and Alabama producers have been of superior quality to those produced by some local manufacturers. This condition, augmented by the propaganda advanced by local dealers emphasizing the higher quality of Georgia brick, in order to justify higher prices for them, has resulted in a prejudice against local products. Many architects, contractors and builders have influenced by this sentiment and have insisted upon Georgia or .Mabama products. Many of the . local brick makers are responsible for this attitude toward local brick in that they have taken little care or pride in the manufacture of their ware and have been content to supply a product of decided inferior quality. Some producers have made qnd more are making common brick that can compete favorably with any of the outside products. In this connection it is interesting to note that in a series of tests made on several Florida, Georgia and Alabama products being con sidered for use in the recent extension of the Capitol at Tallahassee, the Florida products were found to be superior, and were used. Local brick have also been accepted by the federal architect for use in the Post Office building at Apalachicola. ADAPTABILITY OF FLORIDA PRODUCTS As has been pointed out, no Florida clays known at present, are suitable for the commercial production of paving brick, sewer-pipe, and the very highest qualities of face brick. All other structural materials made from clays can be produced in the State. Many of the clays ' now being used for mediocre products can, with the exercjse of a little care in 

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A PRELIMINARY REPORT ON CLAYS OF FLORIDA 249 . manufacturing, be used for products of superi<?r. quality. It is true that the best Florida clays are in the western part of the State and the great est need for them is in the peninsula, but excellent products can be made from many of the peninsula clays . . REASONS FOR FAILURE OF MANY FLORIDA VENTURES More than fifty abandoned brick plants or former locations of plants may be found in v arious parts of the State . This at once raises the question as to why so many brick-producing enterprises have pre-: sumably resulted in failure . Various . reasons may be assigned for this and no one reason would apply in every case. Poor management has, no doubt, caused many of these ventures to fail, and in others a clay unsuited for brick manufacture was used. In some cases, small plants were erected to supply a small local need, and this having been satis fied, the work was discontinued. In one or two cases the limited of clay was exhausted, and in one other case an encroaching sand-dune buried the deposit too deep to make continued manufacture profitable. In a few cases the plants were located at too great a distance from transportation to be satisfactory. POSSIBILITIES AND RESERVES , Probable Continued Expansion . and Development-The extensive expansion and development so noticeable in Florida during the past ten or fifteen years will undoubtedly continue for several gen erati9ns. The large areas of undeveloped agricultural lands, the long growing seasons, and the mild, even climate, will continue to draw home-builders and will cause a permanent and steady increase in gen eral commercial enterprises. The demand for clay products, and particularly structural materi als, will also continue to expand with general growth and development within the State. brick, face brick, hollow block, fireproofing, roofing tile, and floor tile, will be more widely used than now on ac count of the decreasing supply and increasing cost of lumber. Herein, therefore, lies the greatest possibility in the development of the clay industries of this State. All of the products above enumer ated can be produced from Florida clays, and, if not produced in the State, will be imported from adjoining states. Very careful treatment 

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250 FLORIDA GEOLOGICAL SURVEY-15TH ANNUAL REPORT # will be necessary to produce first-class materials from any of the local clays and this will, of course, add to the cost of manufacture. It is very probable, however, that the increased cost of transportation from producers outside of the State will exceed the cost of careful and pains taking manufacture of local products, th1:1s giving the local manufacturer a margin in his favor. The absence of cold weather and the abundance of pine wood ( a t pres ent) for cheap fuel, are additional factors favoring local manufacture. . Extensive draininge programs are now under way in some parts of the State, and many others are being planned . This will enable many of the now swampy areas to be drained, thus opening them up to agricultural and horticultural pursuits. Drain tile will be needed for much of this work, and this likewise can be prOduced locally, affording an opportunity for an industry of considerable magnitude in this line. The stoneware, terra-cotta, and higher grades of clay products, can also be utilized as the demand increases. -It is to be noted, however, that the establishment" of some particularly those for the production of special types of structural material, a s roofing tile , etc., requires the inve s tment of a large amount of capitaL Capable manufacturers, there"fore, will hesitate to risk their money in such enterprises until assured of a large and steady for such wares. 1 ( ( RESERVES As may be seen from Chapter VIII, the clay resources and re .. serves of the State are varied . Some sections, as for example the re gion in the latitude of the ' Everglades, and southward, have practically no clays. Other sections have clays, but none that are of practical value in the manufacture of . clay products. Still others have clays that, with very careful treatment, may be used for products of fair grade. Then, some sections have an almost unlimited supply of excellent clay. For example, Escambia and northern Santa Rosa counties have vast clay reserves suitable for structural materials of excelient grade. The St. Johns River valley, from Jacksonville to Lake George, is underlain by extensive deposits of flood-plain clays, very desirable for common structural materials. 

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A PRELIMINARY REPORT ON CLAYS OF FLORIDA 251 CHAPTER XI METHODS OF PROSPECTIN ; G FOR CLAYS It has been pointed out that this report does not attempt to include the clay deposits of Florida that are not within a reasonable distance from transportation, and as general development continues within the State, it is very probable that many deposits of clays in close proximity to transportation will be found, that are not known at the present time. It is considered expedient, to include a few general sugges tions here for those who may be interested in locating new clay deposits and determining whether o _ r not the clay is of sufficient and proper quality to warrant commercial development. The same sug gestions may be followed by those desiring to determine the available supply or the clay reserves in deposits already known or worked. These suggestions are designed to fit geologic and physiographic conditions in Florida , and while in the principles of clay prospecting are the same for any type of deposit, or in any geologic region, different criteria are to be observed and conclusions drawn in a region of sedi mentary rocks and of lov; relief, as is the case in Florida, from those which are tnost in1portant in crystalline rocks or in a mountainous area. The presence of clay deposits may be detected in wells, in road or railway cuts, in excavations for buildings, along streams, in canals, and in cliffs or banks of lakes, or along the sea shore. It often happens that clay exposures are concealed ul)der a mantle of sand or soil or a dense growth of underbrush. In many places the presence of the clay bed is often revealed by springs or a seepage of water, particularly where the clay stratum is overlain by a porous material, as sand or soil. In some cases clay beds may be detern'lined by the character of the vegetation growing on the surface. In the absence of natural outcrops or expos ures in wells, etc., the presence of clay beds must be determined by borings, which can be done best with a small auger, described on page 253 . . A few preliminary tests should be made upon the clay to de tern1ine whether _or not it is even worth while to prospect the deposit in detail. Tes ts of this character are of little importance in indicating the real value of 'the clay, but, at the same time, the results may be nega tive and show the clay is not suited for use in manufactured products. 

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252 FLORIDA GEOLOGICAL SURVEY-I 5TH ANNUAL REPORT and, therefore, any of time or money in investigating the deposits is useless. These tests are of no value if the clay is being con sidered for Portland cement manufacture. These tests are simple and easily applied, but the results must be interpreted with caution. For examp le , a relatively non-plastic clay may be satisfactorily worked in a dry-press machine, or it may be pos sible to add quantities of other plastic thus making a blend which has sufficient plasticity to worked by the stiff-mud process. The plasticity of the clay may be judged by taking a small moist lump and working it in the hands. If it can be easily molded into various shapes which are retained without cracking as the piece is al lo wed to dry, the plasticity may be considered satisfactory. The pres ence of sand, or other gritty matter, may be easily detected by tasting a small piece of the clay. A small amount of sand or other non-plastic material is not necessarily deterimental for use in structural materials, while, in high-grade clays, such impurities as sand, etc., may be profit ably removed by washing. Calcium carbonate (lime) may be detected by applying a few drops of hydrochloric acid to the clay, which will cause it to effervesce if lime is Calcium carbonate is detrimen tal, causing the product to slake after firing. By far the safest and most satisfactory procedure is to send a sample of the clay, weighing about twenty or twenty-five pounds, to some ceramic laboratory making a specialty of testing clays, where the physical properties of the clay can be accurately determined and its adaptability to various uses arid types of machinery can be ascertained. Many concerns manufacturing clay-working machinery make a prac tice of testing sma ll samples of clay submitted by prospective purchas ers of equipment, and render an opinion as to the suitability of the clay for use in the types of machinery manufactured by them. Also, ar may oftentimes be made with a brick manufacturer at some distance, so that he will not fear competition, whereby the clay-owner may ship a sample of clay, usually several barrels, to be tested by the manufacturer for working and burning in his pla . nt. This method has the disadvantage that the clay to be tested may require entirely different treatment from that given the clay used at the plarit where the test is being made, and, in many cases, the conclusions derived wou ld be er roneous. High-grade clays can only be recognized by the method first listed. After the presence of a clay deposit has been ascertained, it is next of prime importance to know its thickness and the extent of the area 

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A PRELIMINARY REPORT ON CLAYS OF FLORIDA 253 which it underlies, as well as the character and thickness of the over burden or material overlying the clay. It is also desirable to know if the clay is of uniform quality throughout the deposit and, if not, the char acter and extent of its variation. This can best be done by means of an auger, either a "prospector's auger" or an ordinary wood auger. These should be at least two inches in diameter, and should be attached to a shaft or pipe about three-fourths of an inch in diameter. The pipe can be most conveniently handled if it is cut into lengths of about three feet each, so that as the boring increases in depth new joints may be added. A T-joint should be attached to the top so that auger may be rotated. Borings forty or fifty feet in depth may be conveniently made with apparatus of this type. In an area to be prospected, borings should be made about every fifty feet in each direction. A plot, or sketch map, should be made, showing the locations of the holes and an accurate record should be kept of the thickness, character and sequence .of the formations . en countered. In addition to an intelligent record being kept of each hole, sam ples of the materials taken from the boring should be kept and properly labeled. In samples of borings of this type great care must be exercised so that material falling into the hole from above, or scrape<;! off from the upper walls as the auger is withdrawn, is not included with the samples. The samples from each boring, and particularly those from the clay stratum, should be carefully examined, in order to note any ap parent changes in character, laterally or vertically, and to determine its thickness from place to place. Samples taken by an auger are satisfactory for determining the thickness and extent of a clay deposit and any variations which may exist in it. For the determination of the physical properties of the clay, however, larger and cleaner samples are desired than is usually possible to obtain with an auger. Digging a: pit is the most satisfactory method of taking a clay sample. A sample of any size desired can then be obtained and a detailed inspection of the deposit made. For a large deposit several pits should be dug. The location of a clay deposit, with respect to transportation, mar kets, fuel, etc., should be given very careful consideration. A clay suitable only for structural tnaterials would be of little value unless located very near a line of transportation and where there is an ample supply of fuel. 

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254 FLORIDA GEOLOGICAL SURVEY-I 5TH ANNUAL REPORT , APPENDIX A STATISTICS OF PRODUC,.riON OF BRICI< IN FLORIDA, 1 899 TO 1 922 Year. 192 2 19 2 1 1920 1919 1918 1917 1916 1915 1914 1913 1912 1911 1910 1909 1908 1907 1906 1905 1904 1903 1902 1901 1900 1899 Quantity. ( T llousands) 26,2 96 20,163 21,199 16,067 17,681 28,457 31,029 31,019 41 ,9 37 42,450 44,710 36,207 42, 195 46,272 38,559 51,779 42,635 55,242 44,484 36 , 529 31,711 32,253 26,270 26,089 Palue. $201,684 .0 0 164,395.00 312,150.00 185,135 .00 157,314.00 222 , 227.00 188 , 357.00 182,149.00 230,809.00 240,126.00 262,766.00 216,365.00 234,524.00 289,016.00 225,441.00 343,704.00 285,224.00 326,929.00 248 , 579.00 218,086.00 170,852.00 185,759.00 136 ,779. 00 132,123.00 Ave rage price per thousand . $ 7.67 8.15 14.7 3 11.52 8.56 7.63 6.07 5.87 5.50 5.66 5.88 5 . 98 5.56 6.25 5 . 85 6 .64 6 . 69 5.92 5.59 5.94 . 5.39 5 . 76 5 .2 1 5 .06 

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A PRELIMINARY R EPORT ON CLAYS OF FLORIDA 255 APPENDIX B FUSION POINTS OF SEGER CONES Cone T e m pera-Appearance of Chemical Composition ture No. O F o c Heat 022 0.5 Na2 0 } ............ { i Si02 1094 590 0.5 PbO B 2 0 a 021 0.5 Na2 0 } 0.1 AhOs { i 2 Si02 1148 620 0.5 PbO B 2 0 a 020 0.5 Na20 } 0.2 AhOa { i Si02 1202 650 0.5.Pb0 B 2 0 a 019 0.5 Na20 } 0.3 Al20s f i6 Si02 1256 680 0.5 PbO B 2 0 a 018 0.5 Na20 } 0.4 Al20a { i Si02 1310 710 Dull Red Heat. 0 . 5 PbO B 2 0 S 017 0.5 Na2 0 } 0.5 Al20s Si02 1364 740 0 . 5 PbO B 2 0 a 016 0.5 Na2 0 } 0.55 Al20s { Si02 1418 770 0 . 5 PbO B 2 0 a 015 0.5 Na2 0 } 0.6 Al20s { Si02 1472 800 0.5 PbO B 2 0 s 014 0.5 Na2 0 } 0 .65 Al2 0 a f i3 Si02 152 6 830 0.5 PbO B 2 0 S 013 0.5 Na2 0 } 0.7 Al20s { i Si02 1580 0.5 PbO B 2 0 s 860 012 0.5 Na2 0 } 0 .75 Al20s { Si02 1634 890 Cherry Red Heat. 0.5 PbO B 2 0 s 011 0.5 Na20 } 0.8 Al2 0 s { i Si02 1688 0.5 PbO B 2 0 S 920 . 0 1 0 0 . 3 K 2 0 0.2 3.50 Si02 1742 950 0.7 CaO 0 . 3 Al20a 0.45 B 2 0 s 09 0 . 3 K 2 0 0.2 Fe2 0 s 3.55 Si02 1778 970 0.7 CaO 0 . 3 Al20s 0 .50 B 2 0 S 08 0.3 K 2 0 0.2 Fe2 0 a 3.60 Si02 1814 990 0.7 CaO 0 . 3 AI 2 0 s 0 . 4 0 B 2 0 a 07 0 . 3 K 2 0 0 . 2 Fe2 0 s 3.65 Si02 1850 1010 Clear Cherry Red Heat. 0.7 CaO 0.3 Al20a 0.35 B 2 0 a 06 0.3 K20 0.2 Fe2 0 s 3 . 70 Si02 1886 1 030 0.7 CaO 0.3 Al20a 0.30 B 2 0 a 05 0 . 3 K 2 0 0 . 2 Fe2 0 a 3.75 S'i0 2 1922 1050 0 . 7 CaO 0 . 3 Al20s 0.25 B20a 04 0 . 3 K 2 0 0.2 Fe2 0 s 3.80 Si02 1958 1070 0.7 CaO 0 . 3 0.20 B 2 0 s 03 0 . 3 K 2 0 0 . 2 Fe2 0 a 3.85 Si02 1994 1 0 90 0.7 CaO 0.3 Al20a 0.15 B 2 0 a 02 0.3 K 2 0 0.2 Fe2 0 a 3 . 90 Si02 20 3 0 1110 0.7 CaO 0.3 Al20a 0.10 B 2 0 s 01 0.3 K20 0.2 Fe2 0 s 3. 9 5 SiO z 2066 1130 0.7 CaO 0.3 A120 a 0.05 B 2 0 S 

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256 FLORIDA GEOLOGICAL SURVEY-I5'l'H ANNUAL REPORT FUSION POINTS OF SEGER CONES-CoNTINUED C o n e T emperaN o. Chemical Composition ture Appearance of OF oc Heat 0 . 3 K20 0.2 Fe20s } 1 4 S i02 2102 Deep Orange Heat . 0 . 7 CaO 0.3 A l 203 \ 1150 2 0 . 3 K20 0.1 Fe20st } 0.7 CaO 0 . 4 A l20S 4 Si02 2138 1170 3 0.3 K20 0.05 Fe2 0 s } 0.7 CaO 0.45 A )20S 4 S i 0 2 2174 1190 4 0 . 3 K20 } 0.5 A bOa 0.7 CaO 4 Si02 2210 1210 }. 0 . 5 5 0.3 K20 A l 20s 5 Si02 0.7 CaO 2246 1230 6 0.3 K20 } 0 . 6 Al20s 6 Si02 2282 1250 0.7 CaO 7 0.3 K20 } 0.7 Al20s 7 Si02 231 8 1270 0 . 7 CaO 8 0.3 K20 }o.8 A l 20a 8 Si02 2354 1290 0.7 CaO 9 0.3 K20 } 0.9 A bOa 9 Si02 2390 White Heat. 0.7 CaO 1 3 1 0 1 0 0.3 K20 ? A bOa 1 0 S'i0 2 0.7 CaO f 1.0 2426 1330 11 0.3 K20 } 1.2 A ) 20S 1 2 Si02 2462 1350 0.7 CaO 1 2 0.3 K20 } 1.4 A bOa 14 S i02 2498 1370 0.7 CaO 1 3 0.3 K20 } 1.6 Al20s 1 6 S i 0 2 2534 1390 0 . 7 CaO 1 4 0.3 K20 } 1 : 8 A bOa 1 8 Si02 2570 14 1 0 Brigh t White Heat. 0.7 CaO 1 5 0.3 K20 1 AhOs 21 Si02 2606 1430 0 . 7 CaO s 2.1 1 6 0.3 K20 } 2.4 Al20s 24 Si02 2642 1450 0 . 7 CaO 0.3 K20 ? . I 1 7 Al20s 27 S i02 2678 1470 0.7 CaO f 2 . 7 18 0.3 K20 } 3 . 1 Al20s 31 Si02 271 4 1490 . . 0.7 CaO 19 0 . 3 K20 1 A bOa 35 Si02 •2750 1510 . Dazzling Whit e Heat. 0.7 CaO f 3.5 20 0.3 K20 1 Al20a 39 Si02 1530 0 . 7 CaO s .3.9 2 1 0.3 K20 } 4.4 AhOs 44 S'i02 2822 1550 0.7 CaO 22 0.3 K20 ? A l 20a 49 Si02 2858 1570 0.7 CaO s 4.9 23 0.3 K20 ? Al20a 54 Si02 2894 1590 0.7 CaO f 5 . 4 24 0.3 K20 1 Al20a 60 Si02 2930 1 6 1 0 0.7 CaO f 6.0 

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A PRELIMINARY REPORT ON CLAYS OF FLORIDA 257 FUSION POINTS OF SEGER CONES-CoNTINUED Cone Tempera-Appearance of Chemical Composition ture No. O F oc H eat . • 25 0 . 3 K20 J6.6 AI20a 66 Si02 2966 1630 0.7 CaO 261 0.3 K 2 0 } 7.2 . AI 2 0 a 72 Sicr 2 3002 1650 0 .7 CaO 27 0 . 3 K20 } 20 Al20a 200 Si02 3038 1670 0.7 CaO 28 Al20a 1 0 Si02 3074 1690 29 Al20a 8 Si02 ' 3110 1710 30 AbOs 6 Si02 3146 1730 31 Al20s 5 Si02 3182 1750 32 Al20s 4 S'i02 3218 1770 33 AI20s 3 Si02 3254 1 1790 34 Al20s 2,5 Si02 3290 1 810 35 Al20a 2 Si02 1 3326 1830 36 2 Si02 2 3362 1850 37 Al20a 1.66 Si02 3398 1870 38 Al 2 0 a 1.33 Si02 3434 1890 39 Al20a 1 Si02 3470 1910 . 40 Al20a 0 .66 Si02 3506 1930 41 Al20a 0 .33 Si02 3542 1950 42 Al20a 3578 197 0 1Kaolin. 2Clay Schist . 

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258 FLORIDA GEOLOGICAL SURVEY-15TH ANNUAL REPORT . APPENDIX C I DIRECTORY OF FLORIDA CLAY WORKERS . . ( EXCLUS I VE O F FULLER'S E ARTH) Allentown Consolidated School, {near) Milton, Santa Rosa County. Temporary producers of Common Brick. Barrineau Bros. Brick Company, Quintette, Escambia County. Manufacturers of Face and Common Brick and Turpentine Cups. Callahan Brick .and Tile Company, Callahan, Nassau County. Manufacturers of Face a nd Common Brick. Campville Brick Company, Campville, Alachua County. Manufacturers of Common Brick. Clay County Steam Brick Company, Green Cove Springs, Clay County. Manufacturers of Common Brick. Dolores Brick Company, Molino , Escambia County . Manufacturers of Face and Common Brick. Edgar Plastic Kaolin Company, . Edgar, Putnam County. Producers of Refined Sedimentary Kaolin. Florida China Clay Company, Okahumpka, Lake County. Producers of Refined Sedimentary Kaolin. Florida Industrial School for Boys, Marianna, Jackson County . Manufacturers of Common Brick. Florida Pottery, 2430 Euclid Boulevard, St . P e tersburg, Pinellas County . Manufacturers of Ornamental Pottery. . Gamble and Stockton Brick and Tile Company, South Jac ksonville, Duval County. Manufacturers of Face and Common Brick and Interlocking Tile. Glendale Brick Works, Glendale, Walton County. Manufacturers of Common Brick . H. A. Graack & Son Art Pottery, Bradentown, Manatee County . Manufacturers of Ornamental Pot tery. Guilford Bros. Brick Company, Blountstown, Calhoun County. Manufacturers of Common Brick. W . J. Hall and Son Brick Compan y , Chipley, Washington County. Manufacture rs of Common Brick . Keystone Brick Company, Whitney , Lake County. . Manufacturers of Common Brick. Lake County Clay Company, Ok a humpka, Lake County , Producers of Refined Sedimentary Kaolin. McMillan Brick Company, Molino, Escambia County . M anufacturers of Face and Common Brick. Morris and Blumer Brick Company, Brooksville, Hernando County . Manufacturers of Common Brick . Murphy {G . H . ) Brick Company, Argyle, Walton County . Producers of Common Brick . Ocklocknee Brick Company, Lawrence , Gadsden County. (P. 0. Ocklocknee . ) Manufacturers of Common BricJc. Orlando Potteries, Orlando, Orange County. Manufacturers of Ornamental Pottery. Tallahassee Pressed Brick Company, Havana, Gadsden County . Manufacturers of Common Brick. 

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A PRELIMINARY REPORT ON CLAYS OF FLORIDA 259 APPENDIX D . BIBLIOGRAPHY OF FLORIDA CLAYS Crary, 1. W., Sr., Brickmaking and Burning, pp. 3, 14, 35, 1890. Notes occurrences of clay and gives account of manufacture of brick near Pensacola. Davis, N. B., The Plasticity of Clay and Its to Mode of Origin, .Trans. A. I. M. E., Vol. 51, pp. 451-481, 1916. States a possible cause for plasticity of sedimentary kaolins of Florida. Gunter, Herman, Mineral Production in Florida During 1918, Florida Geological Survey, Thirteenth Annual p . 25, 1921. Gives statistics of production for 1918 . and general data. Gunter, Herman, Mineral Production in Florida During 1920, Florida Geological Survey, Fourteenth Annual Report, p. 26, 1922. Gives statistics of production for 1920 and general data. Hall, Archibald A., Analysis of a Florida Clay, Durham University Philosophical Society, Vol. 4, pp. 228-229, 1912. Gives an analysis of a Florida clay. Hill, Robert T., Clay Materials of the United States, in U. S . Geological Survey . Mineral Resources for 1891, p. 507, 1893. Notes occurrences of sandy clays at Tallahassee, Lake City and 1 acksonville. Langenbeck , Karl, The Chemistry of Pottery, pp. 99-101, 1895. Gives analysis of sedimentary kaolin from Edgar. v Matson, George Charlton, Notes on the Clays of Florida, U. S. Geological Survey Bulletin No. 380, pp. 346-357, 1909. General discussion of clays of Florida. Memminger, C . G., Florida Kaolin Deposits, Eng. Min. 1 our., Vol. LVII, p. 436, 1894. Describes occurrences of sedimentary kaolin in Lake County. Meteyard, Eliza, Life of Josiah W edgewood, Vol. I, p. 471, 1865. Gives an account of Florida clays being used in the Wedgewood Pottery, Liver-pool, in 1766. -1 Ries, H., The Clays of Florida, U : S. Geological Survey, Seventeenth Annual Report, Part III ( Cont'd), p. 871, 1898. . Summarizes the general occurrence of sedimentary kaolin and brick clays. Ries, H., The Clays of the United States East of the Mississippi River, U. S. Geo logical Survey Prof. Paper No. 11, pp. 81-86, 1903. Brief account of occurrence of Florida clays. Ries, H., Clays, Their Occurrence, Properties and Uses, pp. 334-335, 1908. Brief account of occurrence of Florida Clays. Ries, H., The Occurrence of High:-Grade American Clays and the Possibilities of Their Further Development, Journal American Ceramic Society, Vol. 1, p . 446, 1918. Notes occurrence of sedimentary kaolin in Lake and Putnam counties. Ries, H., Bayley, W. S.,and Others. High-Grade Clays in the Eastern United States, U. S. Geological Survey Bulletin No. 708, pp. 289-291, 1922. Discusses sedimentary kaolin of Florida. Ries, H., and Leighton, H., History of the Clay Working Industry in the United States, pp. 78-79, 1909. Briefly relates the history of the clay industry in Florida. Sellards, E. H., Mineral Industries, Florida Geological Survey, First Annual Re port, pp. 31-37, ' Discusses briefly the occurrence of common brick-clay and sediment .ary kaolin. 

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260 FLORIDA GEOLOGICAL SURVEY-I 5TH ANNUAL REPORT Seiiards, E. H., Fuller's Earth, Kaolin and Peat in Florida, Eng. and Min. Jour., Vot LXXXV, p. 1187, 1908. Discusses occurrence of fuller's earth and sedimentary kaolin . . Sellards, E. H., Mineral Industries, Florida Geological Survey, Second Annual Re port, p. 242, 1909. Describes briefly occurrences of sedimentary kaolin. Sellards, H., The Florida Phosphate Deposits, Florida Geological Survey, Third Annual Report, p. 22, 1910. Notes occurrence of clays in phosphate formation. Seiiards, E. H., The Soils of Florida, Florida Geological Survey, Fourth Annual Report, p. 21, 1911. ' Gives theory for origin of sedimentary kaolin. Sellards, E. H., The Relation Between the Dunnellon Formation and the Alachua Clays of Florida, Florida Geological S!Jrvey, Sixth Annual Report, p. 161, 1914. . Discusses of Alachua clay formation . Sellards, E . Clay and Clay Products, Florida Geological Survey, Sixth Annual Report, p. 23, 1914. Discusses occur . rence of sedimentary kaolin briefly. Sellards, E. H., Report o.n Clay Tests for Paving Brick, Florida Geological Survey Press Bulletin No. 7, 1915. Gives results of Bureau of Standards tests. Sellards, E. H., Mineral Industries of Florida During 1915, Florida Geological Survey, Eighth Annual Report, p. 19, 1916. Notes location of producers of sedimentary kaolin. Sellards, E. H . , Mineral Industries of Florida During 1916, Florida Geological Survey, Ninth Annual Report, p. 10, , 1917. Notes location of producers of sedimentary kaolin. Sellards, E. H., Geology Between the Ocklockn!!e and Auciiia Rivers in Florida, Florida Geologic .al Survey, Ninth Annual Report, pp. 111-112, 1917. Notes occurrence of clays. in this region: Sellards, E. H., The of Florida, Jour. Am. Ceramic Society, Vol. 1, p. 313, 1918. Discusses occurrences and properties of brick clays and sedimentary kaolin briefly. Sellards, E. H., and Gunter, Herman, Geology Between the Choctawhatchee and Apalachicola Rivers in Florida, Florida Geological Survey, Eleventh Annual Report, p. 83, 1918. Notes occurrence of clays in this region. Sellards, E. H., and Gunter, Herman, Petroleum Possibilities of Florida, Florida Geological Survey, Fourteenth Annual Report, p. 107, 1922. Notes occurrence of sedimentary kaolin in Highland County. Watkins) Joel H., White-Burning Clays of the Southern Appalachian States, Trans. A. I. M. E., Vol. 51, pp. 481-501, 1916. Discusses origin of sedimentary kaolin. Williams, John L., A View of West Florida, p. 69, 1827. Gives an account of Florida brick and clay products being shipped to New Orleans from Pensacola prior to 1827. Williams, John L., Te.rritory of Florida, p. 114, 1 . 837. Notes the shipment of brick and fire-brick to New Orleans from Pensacola prior to 1837. 

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A PRELIMINA RY REPORT O N CLAYS OF FLORIDA 261 INDEX This index does not include the names of persons and corporations mentioned in the financial statement on pages 9-13, the mineral producers on pages 15-23, the fossils in Mr. Mansfield's paper, or the counties in which no clay deposits of im portance were found. All the fossils are listed by famil ies and horizons in the folded table inserted between pages 28 and 29, and the counties are discussed in order on pages 120-215. (See table of contents.) Names of places near which fossils or clay deposits were found are not indexed as a rule, for such references tell nothing about the places themselves. But such localities are indexed under the respective counties. Numbers in parentheses indicate indirect references. A Abandoned brick plants, 112, 129, 130, 137, 156, 157, 171, 177, 187, 188, 196-199, 210, 249 Absorption tests of clay, 101-102 Adams, T. C., chart by, 63,. 98 Adobe, 106 . Aeolian clay , 68 (70) Age of kaolin deposits, 221 Alachua clay, 109, 115, 260 Alachua County, 110, 111, 113, 114, 122, 234 Alkalies in clay, 83 Allentown Consolidated School, 201-204, 212 Allophane, 72 Altoona, kaolin near, 238 Alum Bluff formation, 108109, 113, 114, 160, 170, 217 Alumina, aluminum, in clays, 76, 78, 79, 81 Ammonia in clay, 83 Analyses of clay, 79, 180, 185 Analyses of kaolin, 231, 232 Annutalaga Hammock, 169, 170 Appropriations for Geological Survey, 5 B Baker County, 124-125 Ball clay, 14, 15, 70, 104, 226 Bartow clay, 115, 135, 194, 195 Barrineau Bros., 141, 142, 145, 152, 154, 155 Bastin, E . S., 98 Bath brick, 106 Battery cups, 106 Baumeister, S. J ., 154 Bayley, W. S., work of, 259 Bell, Olio G., 3, 5, 53 Berry, E. W ., work of, 116 Beyer, S. W., work of, 69 Bibliography of Florida clays, 259-260 Biddle, Perry L., 213 Billups, G. P., clay of, 213, 241 Biotite, 83 Black, Hugh, 179 Blake, J. M., 72 Bonding power of clay, 99, 103 Bone Valley .formation, 115, 194 Bottles, clay, 106 Boulder clay, 68 Bradford County, 125 Brevard County, 2 8 ( 41), 125 Brick, production of, 15, 61, 71, 105, 106, 242, 243, 248-249, 254, 258 Brown, Herman, brick maker, 198, 209 Buckle y , E. R., work of, 69 Buckman, H. 0., 67 Buckman & Pritchard, 17 Bureau of Census, U. S., . cooperation with, 14 Bureau of Mines, kaolin tested b y , 230 Burney, C . W., 178 c Calcareous clay, 68, 70, 83, 181 Calcite, 75, 82 Calcium carbonate, 64, 67, 75, 82, 252 Calcium sulphate, 75 (see Gypsum) Calhoun County, 125, 128 Callahan Brick Company, 188 Caloosahatchee formation, 115 Campville Brick Company , ( 15), 121-123 Carbon dioxide, 67, 74, 78, 80, 82 Cement, 71, 85, 106 Chamberlain, W. P., 171, 172 Charlton formation, 115 Chattahoochee formation, 108, 111-112, 158, 159 Chemical analyses of clay, 79, 180, 185, 231, 232 Chemical deposits, 70 China clay, 69, 70 . Chlorite, 76, 83 Choctawhatchee formation, 109, 114-115 Cimolite, 72 Citronelle formation, 115-116, 139, 140, 201, 203 Citrus County, 128, 217, 235 Clapp, F. G., 28, 29 Clarke, F. W., work of, 73 

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262 FLORIDA GEOLOGICAL SURVEY-15TH ANNUAL REPORT Clays, 3, 53-259 classification of, 69-71 definition of, 64-65 origin of, 65-66 suitable for common brick, 122-124, 127-131, 133, 135, 138, 1 54, 157-160, 214 drain tile, 1 22, 127, 129-131, 138, 156, 157, 1 60, 162, 164, 172, 182,186,214 face brick, 214 fire-proofing, 122, 156, 164, 172, 186 furnace linin g, 122 hollow blocks, 1 22, 127, 1 29 , 130, 138, 1 56, 157, 1 60; 1 62, 164, 171, 172, 182, 185, 214 road material, 1 22, 134 , 158, 166, 171, 174, 177, 186, 192 stoneware, 214, turpentine cups, 2 14 Clay County, (114), 128-132, 235 Clay County Steam Brick Company, 131 Clay workers, directory of, ( 15), 258 Cobb, S. E . , Jr. , 5 Collins, Harry L., kaolin of, 238 Coll uvial clay, 69 Collyrite, 72 Color of clay, 90, 103 Columbia County, (114), 133-134 Common brick, 162-214 Conditions of d eposit ion of kaolin, 224 Cone, W. N., 134 Cooke, M . K., 5 Cosner, F. D., 63 Crary, J. W., Sr., 140, 242, 259 Creamcolored brick, 214 Cretaceous clays, 222, 224, 226 Crowder, S. B., clay of, 211 Crucibles, 106 Crystal Springs, 193 D Dade City, 192, 193, 240 Dall, W . H . , 28, 33 Davis, N. B., writings of, 222, 224, 259 Description of clay dep osits, 12 2 DeSoto County, 134, 183, 235 Dexland Bluff, 116, 142, 143, 145 , 148, 149, 151, 152, 155 Dexter, Chas. A., 139, 143 Diatomaceous earth, 16 Dick, M., 72 Distribution of clay d epos its, 1 22 D o lomit e , 76, 82, 83 Dolores Brick Company, 141, 147, 148, 150, 155, 156 Drain tile, 214, 243 Dunne1lon formation, 115, 260 Duval County, 135-138 E Edgar, C. S . , 226 Edgar Plastic Kaolin Company, 14, 15, 2 19, 220, 223, 226, 229, 240 Edgar, kaolin mines, 14, 217, 226, 229,240 Edwards, R. J., 2 1 2, 213 Efflorescence on clay or clay products, 85-88 Emery wheels, 106 Eocene, 107-108, 110 Epidote, 78 Escambia County, 116, 138-157, 246, 247 Estiffanulga Bluff, 182, 183 Estuarine clay, 70 Expenditures of the s urvey, 8 -1 3 F Face brick, 154, 172, 182, 18 8, 200, 2 14 , 243, 247, 258 Fat clay, 89, 100 Feldspar, 65, 66, 72, 73, 80, 222, 223, 244 Filter tubes, 106 Fire-boxes, 122 Firebrick, 106, 140 Fire-clay, 70, 71, 104, 1 40 Fire-proofing, 105 Fire shrinkage of day, 101 Flagler County, 157 -158 Flint, production of, 17 Flint clay, 70 Flocculation, 68 Flood-plain clays, 68, 70, 110, 117, 16 . 1 164 Florida China Clay Corporation, 15, 225, 228 , 231-237 Florida Diatomite Company, 16 Florida Geological Survey, work of, 6 Florida Industrial School for Boys, 172, 173 Floridin Company, 160 Flower pots, ( 106), 2 14 Flues, 106 Fluxi9g impurities, 79 Foster Kaolin Co., 240 Front brick, 105 Fuller's earth, 16, 62, 63, 113, 1 21, 160, 185, 221, 245, 260 underlying kao lin formation, 237, 240 Fulton, W. A. , 63 Furnace linin gs, 122 F1usibility of clay, 93-97 

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A PRELIMINARY REPORT ON CLAYS OF FLORIDA 263 G Gabbro, 65 Gadsden County, 63, 111, 114, 158-164 Gamble & Stockton Co., 135-137 Garnet, 77, 81, 82 Georgia, white clays of, 216, 224, 226 Geography of central and southern Flor-ida, 8 Gill, A. C., on origin of kaolin, 224 Glacial clay, 68, 70 Glasenapp, M., 77 Glauconite, 76, 81 Glendale Brick Works, 212 Gonzalez, Mrs. S. J., 242 Goss, J. J., 201 Graack & Sons Pottery, 15, 103, 183, 244 Green Cove Springs, 128, 131 Greensand, 7 6, 8 3 Greer, E. E., 238 Griffin, 84 Grimsley, G. P . , 69 Grout, F. F . , 69, 70 Guilford, Bros., Brick Co., 126-128 Gull Point, 142-146, 148 Gumbo clay, 106 Gunter, Herman, 65, 235, 259, 260 Gypsum, 7 5, 82 H Hall, A . A., 259 Hall Brick Co., 214, 215 Halloysite, 72 Hamilton County, 111, 164-165 Hardee County, 165-166 Harper, R. M., (8), 18, 106, 196 Hematite in clay, 74, 81 Henry, A. M., 185 I Hernando County, (112), 166-170, 217, 235 Hickling, G., 72 Highlands County, 170, 235 Highlands Farms, 195 Hilgard, E. W., 65 Hill, R. T., 259 Hillebrand, W. F., . 80 Hillsborough County, (112), 114, 170-172 Hollow blocks, 171, 214, 243 Holmes County, . 111, 172 Hornblende, 77, 80, 81, 83 Hydraulic removal of kaolin overburden, 233, 234 Hydromica, 73, 78, 80 I Ilmenite, 17, (76), 84 Indianaite, 69, 72 Insulators, 106 International Kaolin Co., 226 Iron in clay, 81, 82, 140, 142 Iron 74 Iron dioxide, 64, (74), 78, 79, 81 Iron sulphate, 87 Iron sulphid_e, 74 J Jackson County, 111, Jacksonville formation, 109 Jardinieres, jars, 243, 244 Jefferson County, 112, 173-174 Jennings, Bryan, 130 Johnson, L. C., work of, 14 . Johnson, S. W., work of, 72 K Kaolin, 14, 15, 63, 104, 117, 216, 219, 226, . 231, 232, 244,_258, 260 Kaolinite, 64, 71, 72, 73, 78-81 Kennedy, T. S., 63 Key, A. J., 161 Keystone Brick Co., 176 Kissimmee, 35, 192 Klein, A. A., 77 Kleiser, R. F., 237, 238 Klocker, J. H., 240 Kohler pottery or ware, 143, 244 L tacustrine clay, 68, 70, 110 Ladd, G. E., 69, 76 Lafayette formation, 116 Lake County, 14-16, 63, 114, 174, 235-238 Lake County Clay Co., 15, 226, 235, 236, 239 Lake region, 189, 217 Lakes, 110 Lampson, J as., 240 Langenbeck, Carl (Karl), 232, 259 Larsen, E. S., 72 Leaching, 66 Lean clay, 89, 100 Leighton, H., 259 Leon County, 113, 114, 177-180 Levy County, 111, 180-181, 217, 238 Liberty County, 181 Lime, 17, 65, 7 5, 78-80, 82, 83, 134 Limestone, 8, 17, 67, 69, (82) Limonite, 74, 81, 140, 142, 154 Link, J. H., 181 Live Oak, 207, 241 Lloyd, George T., 131, 132 Lloyd, Strauss L., 5 Lyle, W. H., 207 

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264 FLORIDA GEOLOGICAL SURVEY-15TH ANNUAL REPORT Me McLaughlin, W. J . , 183-185 McMillan Brick . Co., 150, 156 M Mackler, Dr., 87 Magnesia, magnesium, 65, 76, 78, 83, 134 Magnesium carbonate, 64 Magnetite, 74 Majolica, 106 Manatee County, 63, 113, 134, 183-185 Manganese, 77,. 90 Mann, Albert, quoted on diatoms, 16 Mansfield, \V. C., 3, 25 Marbles (clay), 106 Marianna formation, 108, 111, 172 Marion Coun ty, 111, 113, 114, 185-186, 238 Marine clays, 68, 70 Marls, 8, 208, 210 Matson, G. C., 28, 29, 221, 259 Mate x: i a Is underlying kaolin-bearing formation, 219, 240 Mellor, J. W., 77 C. G., 259 H. D., 6 . 3 Meteyard, Eliza, 138, 242, 259 Methods of mining kaolin, 233 Merrill, G. P., 64, 67, 76 Mica, in clay, 66, 67, 73, 80, 81, 83, 142, 218, 222, 224, 227, 241 Mineral City, 17 productions of Florida, 14-23 Mineral waters, output of, 23 Mineralogy of Florida kaolins, 232 Minerals in clays, 71 Mining of kaolin, methods used in, 233234 Miocene, 35-37, Minton, J. T., 200 Mirror Lake, kaolin around, 240 Molding sand, 192 Morris & Blumer Brick Co. , 166-168 Montmorillonite, 72 Mooney, Frank, 130 Murphy, G. H., 202, 212 Muscovite, 73 N Nashua (marl) formation, 28-35, 115 Nassau County, (28), 29, 40, 86-189 National Lead Co., 17 Nelson, P . A. J., 191 Newlands, C. 0., 35 N ewtonite, 72 Nuckolls, B. H., 174 0 Ocala formation, 107-108, 110, 124, 166, 185 Ocklocknee Brick Co., 117, 162, 163, 258 Okahumpka, kaolin mined near, 217, 226-237, 239 . Old Brick Yard Landing, 187, 188 Oligocene, 108, 111, 112 Orange County, 114, 189-191 Organic matter in clay, 78, 79, 84 Origin of kaolin deposits, 221 Orlando Pottery, 15, _ 189, 190, 244 Orthoclase, 83 Orton, E., 64, 69 Orton, E., Jr., 69, 84, 85, 94 Osceola County, 28, 29, 35, 36, 191-192 p Pablo Beach, 17 Palatlakaha River, kaolin deposits on, 235, 236 . Paper filler, 71, 106 Parmelee, C. W., 69, 70, 71, 86 Pasco County, 192-194, 217, 240 Paving brick , 105 Peace Valley Farms Co., 196 Peat, 8, 17 Pensacola, 138, 140, 143, 242, 260 Pensacola Brick Co., 1 . 55, 156 Pholerite, 72 Phosphate, 18.:.20, 115 Phosphatic clay, 194 Physical properties of kaolin, 229, 230 Pigments, 71, 106 Pinellas County, ( 112), 114, 194 Pitchers (clay), 106 PJans .of the Survey, 8 Plasticity of clay, 89-90, 100, 101, 222 Platt Bros. brick plant, 137, 138 Pleistocene, 40-42, 109, 110, 116, 117, 139, 140 Pliocene, 27, 29, 109, 110, 115 Polishing brick, 106 Polk County, 114, 194-197, 240 Porcelain, 106, 232 Porosity of clay, 97, 99, 102 Potash, 65, 78, 83 Potassi urn, 7 6 Potteries, 15, 121, 138, 243, 245, 258 Pottery, 106, 138, 145 Powell, W . B . , 63 Probable age of kaolin deposits, 224 Production of brick, statistics of, 254 Psilomelane, 77 Publications issued by the Survey, 7 Pumps, 106 

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A PRELIMINARY REPORT ON CLAYS OF FLORIDA 265 Putnam County, 14, 28, 29, 31, 38, 39, 63, 197,240 Pyrite, 74, 81, 87 Pyrolusite, 77 Pyrophyllite, 72 Q Quarterman, B. S., 240 Quartz, 14, 66, 72, 73, 80, 81. , 218 Quincy, 160, 161 Quintette, 145, 154 R Railroad ballast, 106 Ranson, Robert, 17 Rectorite, 72 Refractory clay, 70 Residual clay, 66, 67, 69, 72, 110, 11l Retorts, 106 Reusch, H., 72 Richbourg, D. J ., 124 Richmond, kaolin, 236 (see Okahumpka) Ries, H., 63-65, 67, 69, 72, 79, 81, 82 , 84; 89, 92, 93, 96, 98, 179, 180, 218-222, 259 Road metal, 106 Roofing tile, 145, 154 Royston, Ed, 159 Rutile, 76, 78, 84 s Saggers, 106, 244 St. Johns County, 200-201 Sand and gravel, production of, 22 Sand-lime brick, 22, 247 Santa Rosa County, 201-205 Schaffer, I. L., 153 Schurecht, H. G., 77 Schrotterite, 72 Scove kilns, 202, 204 Sections indicating thickness of kaolin, 236, 237, 240 Sedimentary clay, 66-68, 72 Sedimentary kaolin, 117, 121, 193, 21624-1, 244, 245, 258-260 Seger cones, 96-98, 135, 244, 255-257 Selenite, 76 Sellards, E. H., 28, 29, 109, 125, 138, 191, 196, 207, 217, 218, 221-223, 235, 259, 260 Sericite, 73 Serpeptine, 65 Sewer pipe, 106, 247, 248 Shale, 70 Shell Bluff, 157 Short clay, 89 Shrinkage of clay, 91-93, 100, 101 Shuttle eyes, 106 Siderite, 74, 81 Silica, 65, 78-80 Silicates, 64, 65, 71, 72, 82, 83, 90 Sink-holes, 109, 110, 115 Sillimanite, 78 Slaking of clay, 91, 100 Slip clay, 106 Soda, 65, 76, 78, 83 Soil, definition of clay, 65 Soluble salts in elay, 85-88, 193 Somers, R . E., 71, 73, 76 .... 78, 232 Soper, E. K . , 69, 70 South Carolina, white clays of, 216, 226 Southern F'arm Land Co., 157 Spanish settlements, 242 "Spark plugs, 232 Staley, H: F., 85, 87 State Hospital, Chattahoochee, 158-162 Statistics on mineral production, 14-23 Stoneware (clay), 104, 145, 154, 214, 243 Stoutamire, J. D., 179 Stoutamire, W . B., 179, 180 Strait, Allen, 63 Stratigraphy, 107 Strength of clay, 99, 102-103 Sulphur, 74, 78, 79, 83, 85 Sumter County, 206, 217 Suwannee County, 111, 207, 217 T Tallahassee Pressed Brick Co., n 7, 164 Tampa Brick Co., 171 Tampa formation, 108, 112, 166, 170-172 Taylor, C. B . , 63 Tedder, C. H., 63 Temple Terrace, 171 Tensile strength of clay, 102 Terra-cotta, 104-106, 145, 154, 250 Texture of clay, 91 Thermoelectric pyrometer; 97 Thickness of kaolin formation, 236, 237, 240 Thompson, R. W . , 213 Tile, 106, 243, 250 , 258 Titanic acid, 78 Titanite, 78 Titanium, ( 7 6), 80, 84 Tombstones, clay, 106 Tourmaline, 78 Trail Ridge, 135 Transported clays, 70 Transverse strength of clays, 102 Turpentine cups, 106, 127, 138, 154, 214, 243, 248 Tuyeres, 106 

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266 FLORIDA GEOLOGICAL SURVEY-I5'l'H ANNUAL REPORT u Umbrella stands, 1 06 Unite d States Bureau of Standards, 138, 174, 191, 196, 205, 207, 211 United States Geological Survey, 14, 63 Urns, 243 Utica Brick & Tile Co., 197 Uses of Florida kaolin, 232 v Vanadium, 86 Vases, 15, 243, 244, 245 Vaughan, T. W ., 28, 29, 34, 260 Veatch, J. Otto, 28, 29, 76, 84 Vernad sky, W . , 77 Vitri fied brick, 106 Vivianite, 77 Vol usia County, 28, 29, 32, 41, 208-211 w Wad clay, 106, 244 Wakulla County, 211 Walton County, 2 112 13, 2 1 7 , 241 Washington County, 214-215 \Vashington, H. S., 80 \V ash tubs, 1 06 \Vater in clay, 84 Watkins, J . H., 22 1, 222, 224, 260 Weathering, 65 Wedgewood, J os iah, 138, 242, 259 Wheeler, H. A . , 64, 69 Whitney Brick Co . , 176 Williams, I. A., 69 Willi a ms, John L ee, 138, 1 40, 242, 260 Willi ams, W . W., 179, 180 Wood, C . Lindley, diatomite, 16 Worthington, J. E., 63 

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