GASTROPODS: TROCHIDAE TO TURRITELLIDAE


 No. USGS
 used in Cenozoic Field Description of locality this No. No. report

 CULEBRA FORMATION, GAILLARD CUT, CANAL ZONE
 98 16942 35a West side of Gaillard Cut, canal station 1600.5 Float from Culebra formation. T. G. Moran and W. P. Woodring, 1947. Not plotted, same as locality 120.
 99 6019 Lower half of section near Las Cascades, exact horizon not known. D. F. MacDonald and T. W. Vaughan, 1911. [Presumably float near canal station 1610.] Not plotted. 99a 6019a Near canal station 1611. D. F. MacDonald and T. W. Vaughan, 1911. Also larger Foraminifera (Cole 1953a). Plotted on plate 2. [Localo ities 6019a to 6019g, inclusive, are located between canal stations 1606 and 1611 and are arranged in upward sequence in that order. For stratigraphic section see MacDonald, 1919, p. 537-538 and for general location see MacDonald, 1919, pl. 154. Location with reference to the canal stations are taken from manuscript structure sections prepared by MacDonald. The constructionperiod localities in Gaillard Cut presumably represent the excavated prism of rock. Those plotted are shown by the symbol for submerged localities, though many may be above the level of the canal.] 99b 6019b _-_-- Near canal station 1611. D. F. Mac-.
 Donald and T. W. Vaughan, 1911. Not plotted.
 99c 6019c __-_Canal station 1610. D. F. MacDonald and T. W. Vaughan, 1911. Not plotted.
 99d 6019d Canal station 1609. D. F. MacDonald and T. W. Vaughan, 1911. Not plotted.
 99e 6019e Near canal station 1608. D. F. MacDonald and T. W. Vaughan, 1911. Not plotted.
 99f 6019f Near canal station 1607. D. F. MacDonald and T. W. Vaughan, 1911. Also larger Foraminifera (Cole, 1953a). Not plotted. 99g 6019g Canal station 1606. D. F. MacDonald and T. W. Vaughan, 1911. Also larger Foraminifera (Cole, 1953a). Plotted on plate 2. [Assigned by MacDonald to Emperador limestone member, but apparently represents a sandy limestone referable to the Culebra formation proper.]

 I The canal stations are located along the center alinement of the canal it intervals of 100 feet (30.5 meters) and are numbered from the Caribbean terminus to the Pacife terminus.


No. USGS used in Cenozoic this No. report


99h 100







I00a 100b 101





102 102a 103


104 104a 104b 105


Field No.


 Description of locality



CULEBRA FORMATION, GAILLARD CUT,
 CANAL ZONE-Continued


5857 ----_ Near canal station 1610. D. F. MacDonald, 1911. Not plotted, practically same as locality 99c.
6020a --_-- Near canal station 1614. D. F. MacDonald and T. W. Vaughan, 1911.
 Plotted on plate 2. [Localities 6020a to 6020c, inclusive, underlie 6019a (MacDonald, 1919, p. 538).
 Type locality of "Orbitolites"
 americana.]
6020b -- Near canal station 1614. D. F. Mac.
 Donald and T. W. Vaughan, 1911.
 Not plotted.
6020c _---- Near canal station 1613. D. F. MacDonald and T. W. Vaughan, 1911.
 Also corals (Vaughan, 1919a, p. 208).
 Not plotted.
16943 34 West side of Gaillard Cut, canal station 1619. Black clay 60 centiseters below base of limestone. T.
 G. Moran and W. P. Woodring,
 1947. Plotted on plate 2.
6012a --- Near canal station 1723. D. F. MacDonald and T. W. Vaughan, 1911.
 Plotted on plate 2. [For stratigraphic section including localities 6012a and 6012b see MacDonald, 1919, p. 537 and for general location
 see pl. 154.]
 6507 --. - Lower part of Culebra formation about 0.25 mile (300 meters) south of Empire bridge, altitude 55 feet (17 meters). D. F. MacDonald, 1911. (Probably near canal station
 1720.) Not plotted.
6012b ---__- Near canal station 1717. D. F.
 MacDonald and T. W. Vaughan,
 1911. Plotted on plate 2.
16933 31 West side of Gaillard Cut, canal station 1730. Sandy pebble bed in almost black mudstone. T. G.
 Moran and W. P. Woodring, 1947.
 Plotted on plate 2.
 6976 --- Culebra (Gaillard) Cut, about midway between Empire and Culebra, about 50 feet (15 meters) below original surface. Received from George Gaillard, 1909. [Presumably near
 canal station 1730.] Not plotted. 5863 ------ Conglomerate near canal station 1731, about 0.3 mile (0.5 kilometer) below Empire bridge. D. F. MacDonald,
 1911. Not plotted.
 6517 -- East side of canal opposite Culebra railroad station. D. F. MacDonald, 1913. [Between canal stations 1750
 and 1760.] Not plotted.


121