﻿GEOLOGY AND PALEONTOLOGY OF THE CANAL ZONE. 577 



AOE OF THE SeDIMENTART FORMATIONS OF PaNAMA, AND THE DISTRIBUTION OF 



THEIR Age-Equivalents in Central America and the West Indies. 



EOCENE. 



The oldest deposit from which Eocene fossils were obtained is a 

 dark-gray argillaceous sandstone near Tonosi. Here specimens of 

 Venericardia planicosta closely resembling a variety found at Clai- 

 borne, Alabama, were collected. The evidence of one species is 

 meager, but as much as there is points to the deposit being of 

 Claibornian-Lutetian (or Auversian) age. 



Deposits of Claibornian age extend as a belt from South Carolina 

 across Georgia into Alabama, thence through Mississippi, eastern 

 Arkansas, Louisiana, and Texas, and into Mexico.* 



Although deposits of upper Eocene (Jacksonian) age have not 

 been positively identified in Panama, they probably are there. 

 Doctor Cushman inclines to the opinion that the limestone contain- 

 ing Orthoj)Tiragmina minima at David is of upper Eocene age. Upper 

 Eocene deposits occur in Nicaragua, St. Bartholomew, Jamaica, 

 Cuba, in the southeastern and southern United States from North; 

 Carolina to Mexico, and probably in northern Colombia. The cor- 

 relation and distribution of deposits of this age are discussed on 

 pages 193-198 in the account of the fossil coral-faunas. They are 

 the American representatives of the European Bartonian-Ludian- 

 Priabonian stage. 



It is highly probable that upper Eocene marine sediments are- 

 present on the island of Antigua. Hussakoff has described ^ a fossil 

 fish, Zehrasoma deani, from a quarry belonging to Mr. Oliver Nugent. 

 I did not visit this quarry but saw it from a distance. It is at a 

 place known as Golden Grove, which is 1.4 nautical miles nearly due 

 south from the Cathedral in St. John, about 400 feet east of the 

 southern end of a north and south line, and is in a sandstone or 

 bedded tuff that is stratigraphically below the middle Oligocene 

 Antigua formation. I believe Hussakoff is correct in assigning a 

 probably Eocene age to the fossil. 



Although it is probable that deposits of upper Eocene age occur 

 in a number of other West Indian islands, Haiti, Porto Rico, the 

 Virgin Islands, St. Croix, Guadaloupe, Martinique, and Barbados, 

 the available evidence is indecisive. Gregorj^ ^ expressed the opin- 

 ion in 1895 that the Scotland "beds" of Barbados arc of lower 

 Oligocene age. 



According to Douville, in his latest paper* on the orbitoids of 

 Trinidad, there are in that island deposits of Lutetian, Auversian, and 



• See p. 565 of this volume. 



' HussakoiV, L., Zcbrasoma deani, a fossil surgeon fish from the West Indies, Amcr. Mus. Nat. Hist. Bull., 

 vol. 23, pp. 12.5, 126. pi. 7, 1907. 



' Gregory, J. W., Contributions to the paleontology and physical geology of the West Indies, Gcol, 

 Soc. London Quart. Journ., vol. 51, p. 298, 1895. 



<Comptes Rend., vol. 1G4, pp. 841-847, 1917. 



