GEOLOGY AND PALEONTOLOGY OP THE CANAL ZONE. 577 



Age of the Sedimentary Formations of Panama, and the Distribution op 

 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. 1 



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 Orthopliragmina 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 2 a fossil 

 fish, Zebrasoma 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. Gregory 3 expressed the opin- 

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

 Oligocene age. 



According to Douville, in his latest paper 4 on the orbitoids of 

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



1 See p. 565 of this volume. 



* Hussakoff, L., Zebrasoma deani, a fossil surgeon fish from the West Indies, Amer. Mus. Nat. Hist. Bull., 

 vol. 23, pp. 125, 126, pi. 7, 1907. 



s Gregory, J. W., Contributions to the paleontology and physical geology of the West Indies, Geol. 

 £oc. London Quart. Journ., vol. 51, p. 298, 1895. 



* Comptes Rend., vol. 104, pp. 841-847, 1917. 



