GEOLOGY AND PALEONTOLOGY OF CANAL ZONE


 A posthumous publication. Discussion of geology
 includes some modification of MacDonald's earlier views. Geology of slide area in Gaillard Cut is
 shown on detailed map (scale, 1 inch=465 feet). 1947. [Thompson, T. F.J, Geology: Panama Canal, Rept.
 Governor under Public Law 280, 79th Cong., 1st
 Sess., Annex 3, 30 p., 8 figs.
 Geology of proposed sea-level canal is summarized. 1947. [Thompson, T. F.], Geology: Idem, App. 8, 84 p., 38 figs.
 Geology of proposed sea-level canal. Areal geology
 is shown on strip maps, scale 1:40,000 and 1:20,000. 1948. Cooke, C. W., Eocene echinoids from Panama: Jour.
 Paleontology, v. 22, p. 91-93, pl. 22.
 Eocene echinoids collected in Madden basin during
 field work for present report.
1949. Woodring, W. P., and Thompson, T. F., Tertiary formations of Panama Canal Zone and adjoining parts of Panama: Am. Assoc. Petroleum Geologists Bull.,
 v. 33, p. 223-247, 2 figs.
 Summary of stratigraphy and paleontology of
 Tertiary formations.
1949. Cole, W. S., Upper Eocene larger Foraminifera from the
 Panama Canal Zone: Jour. Paleontology, v. 23, p.
 267-275, pls. 52-55.
 First published record of Eocene deposits in Canal
 Zone. The fossils were collected at locality 29 of
 present report.
1949. Bermddez, P. J., Pavoninoides, a new genus of the Miliolidae from Panama: Cushman Lab. Form. Research
 Contr., v. 25, pt. 3, p. 58, 1 fig.
 Pavoninoides panamensis, from "marly limestone
 of the Oligocene (probably middle), Madden Lake."
 Though the locality is indefinite, the limestone presumably is in Gatuncillo formation.
1949. Rubio, Angel, Notas sobre geologla de Panamd: Panam6,
 Ministerio de Educacisn, Depto. de Cultura y Publicaciones, 183 p., 32 figs.
 Compilation of data on geology of Panamfi.
1950. Pilsbry, B. A., and Olso, A. A., Review of Anticlimax,
 with new Tertiary species (Gastropoda, Vitrinellidae): Bull. Am. Paleontology, v. 33, no. 135, 22
 p., 4 pls.
 Includes Anticlimax gatunensis and A. teleospira,
 from lower part of Gatun formation.
1939. Jones, S. M., Geology of Caun Lake used vicinity,
 Panama: Geol. Soc. America Bull., v. 61, p. 893-922
 2 pls., 2 figs.
 Geology of Gatun Lake area. Includes a geologic map, scale 1:125,000.
1952. Drooger, C. W., Study of American Miogypsinidae, 80
 p., 3 pis., 14 figs., Zeist, Netherlands.
 Includes species from Caisnito formation and
 Culebra formation, including Emperador limestone
 member.
1952. Thompson, T. F., Ring dikes of the continental divide
 region, Panama Canal Zone (abstract): Geol. Soc.
 America Bull., v. 63, p. 1396, 1992.
 Ring-shaped and cup-shaped dikes surrounding
 hills of agglomerate ie Gaillard Cut area.
1953. Cole, W. S., Eocene and Oligocene larger Foraminifera
 from the Panama Canal Zone and vicinity: U. S.
 Geol. Survey Prof. Paper 244, 41 p., 28 pls., 2 figs.,
 1952 [19531.
 Eocene and Oligocene larger Foraminifera collected during field work for present report.


1953. Cole, W. S., Some late Oligocene larger Foraminifera from
 Panama: Jour. Paleontology, v. 27, p. 332-337, pls.
 43, 44.
 Species in MacDonald's collections from Culebra
 formation, including Emperador limestone member, and La Boca marine member of Panamd formation. 1954. Bramlette, M. N., and Riedel, W. R., Stratigraphic value
 of discoasters and some other microfossils related to Recent coccolithophores: Jour. Paleontology, v. 28,
 p. 385-403, pls. 38-39, 3 figs.
 Includes records of discoasters from Gatuncillo
 and Culebra formations.
1955. Woodring, W. P., Geologic map of Canal Zone and adjoining parts of Panamg,: U. S. Geol. Survey, Misc.
 Geol. Invest., Map I-1, scale 1:75,000.
 Reproduced with minor alterations as plate 1 of
 present report.
1956. Terry, R. A., A geological reconnaissance of Panama:
 Calif. Acad. Sci. Occasional Paper 23, 91 p., 3 pls.,
 8 figs.
 A general account of the geology of Panam,
 including Canal Zone. Published after present
 report was prepared.
1957. Cole, W. S., Late Oligocene larger Foraminifera from
 Barro Colorado Island, Panama Canal Zone: Bull.
 Am. Paleontology, v. 37, no. 163, p. 309-338, pls.
 24-30.
 Description of species from Bohio and Caimito
 formations of Barro Colorado Island.

 GEOLOGY
 STRATIGRAPHY
 OUTLINE OF STRATIGRAPHY
 The region covered by plate 3 embraces all except the extreme western part of a Tertiary marine sedimentary area which may be designated the central Panama area (fig. 1). The boundaries of the areas shown in figure 1 represent the approximate known e_:tent of Tertiary marine formations, not the outlines of depositional basins. In the central PanamA area, Tertiary marine formations extend across the continental divide.
 The stratigraphy in the region covered by plate 1 is notably different from place to place. For the purpose of description six main regions are recognized: Quebrancha syncline, Madden basin, Gatun Lake area, Caribbean coastal area, Gaillard Cut area, Pacific coastal region in Panamn east of the Canal Zone. Quebrancha syncline and Madden basin are structural features east of the Canal Zone. Gaillard Cut, designated Culebra Cut during the construction period, is the part of the canal excavation beginning opposite the south end of the Panama Railroad bridge across Rio Chagres at Gamboa and extending southeastward, across the continental divide, to the north end of Pedro Miguel Locks. The correlation of the formations in different areas is shown in figure 4.
 The basement on which the Tertiary formations rest consists principally of altered and strongly deformed volcanic rocks, including tuffs that contain marine


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