CONTENTS


-bstract --_ __- -- _- _- -_-_Introduction _-____ ------------Historical background -- -- - 
 Purpose and scope of report
 Orthography of geographic names
 Acknowledgments _-_ ---..Annotated bibliography G eology ------ -_-_-_-_ --_-_-_---_-_Stratigraphy -- - - - --_-_-_Outline of stratigraphy
 Cretaceous(?) system Eocene series --- --_Gatuncillo formation
 Eocene or Oligocene series
 Marine member of Bohio(?) formation -O ligocene series -- ..-_--- _--_---_ --__ -__ ----.
 Bohio formation -_-- ----_-- _Caimito formation, exclusive of Madden
 basin and Pacific coastal area _-.--..-.Tuffaceous strata in Chorrera area_-------Bas Obispo formation and Las Cascadas
 agglom erate_ .. .... .... ...-_-- __- _..
 Oligocene and Miocene series -- -----..
 Caimito formation of Madden basin and
 Pacific coastal area --- ._.._---- _-_----Miocene series.-......-_-..-...---.....
 Culebra formation, including Emperador
 lim estone m ember --- ...-...._.. ---. ..
 Cucaracha formation _---- ____---- ___.-_PanamA formation, including La Boca
 marine member and Pedro Miguel agglomerate member --- .--- -- _-- __-....
 G atun form ation ___--._-_--.._ -_ -__.. -_Pliocene series ..-_ -- --- ..-_-----Chagres sandstone, including Toro limestone m em ber-.-.. -.. --.-_ ---_ ___-._Pleistocene series___- .-- ___-- _- .- ...-------.
 Correlation of Tertiary formations in different


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Geology-Continued
 Igneous rocks --__ --__--_ ---Cretaceous(?) volcanic and intrusive rocks.
 Tertiary volcanic and intrusive rocks --Granular intrusive rocks
 Dike rocks _--- -------Volcanic rocks and tuf
 Chemical composition -A g e - -_ -_ - --_-_-_ --_-.- -_Structure _-_-- -- _-- 
 Structural history Structural features ___ 
 Mineral resources ---- ..-_ --_Metallic mineral deposits
 Nonmetallic mineral deposits
 Oil possibilities --_-_- -------Description of Tertiary mollusks
 Gastropods -- .Family Trochidae _-_ - Family Turbinidae
 Family Phasianellidae 
 Family Phasianellidae?
 Family Neritidae
 Family Thiaridae?
 Family Littorinidae Family Vitrinellidae
 Family Rissoidae
 Family Rissoinidae
 Family Xenophoridae Family Hipponicidae Family Hipponicidae?
 Family Crepidulidae
 Family Calyptraeidae
 Family Naticidae
 Family Turritellidae
Localities at which fossils were collected References cited ___Index- ------


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 ILLUSTRATIONS


 [Plates 1, 2 in pocket, plates 3-23 follow p. 145]

PLATE 1. Geologic map of Canal Zone and adjoining parts of Panam -----------In I
 2. Geologic map of Gaillard Cut area, Canal Zone -__-_-_-_-_-.. --_-_--- --------------- In
 3. Foraminiferal limestone from Gatuncillo formation of Madden basin, Panami.
 4. Echinoid-bearing limestone from Gatuncillo formation of Madden basin, Panam.
 5. Boulder conglomerate of Bohio formation at Salud Point, Barro Colorado Island, Canal Zone.
 6. Poorly sorted conglomerate of Bohio formation on Transisthmian Highway near Las Cumbres, just south of
 continental divide, Panamd.
 7. Alhajuela sandstone member of Caimito formation at north abutment of Madden Dam, Canal Zone.
 III


pocket ocket


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areas.