GEOLOGY AND PALEONTOLOGY OF THE CANAL ZONE. 595 



line map of the Pliocene area in Yucatan, 1 and, he repeated Heilprin's 

 lists of fossils. 



No information is available for British Honduras, the Republic of 

 Honduras, or Nicaragua. 



The accompanying table presents the approximate stratigraphic 

 equivalence of the Tertiary marine formations in Central America, the 

 Antilles, the southeastern United States, and Europe. It will be 

 noticed that the table indicates two great stratigraphic bieaks, 

 namely, one in lower and middle Eocene time, the other in upper 

 Miocene time. 



Pre-Tertiary Formations in Central America and the West Indies. 



The foregoing discussion of the marine geologic formations of 

 Panama has included more or less consideration of all of those of 

 Tertiary age, concerning which we have knowledge, in the southern 

 United States, eastern Mexico, Central America, and the West Indies, 

 and a few notes have been made on northern South America. Since 

 the publication of Bailey Willis's Index to the stratigraphy of North 

 America, 2 there has been no important addition to our knowledge of the 

 pre-Tertiary formations of the West Indies and Central America. As 

 this volume and the geologic map of North America it was prepared 

 to accompany are both easily accessible to geologists, and as a review 

 of the formations of those ages would be mostly repetition of informa- 

 tion contained in that work, I will make only a few general remarks. 



Rocks of supposed Archean age outcrop as follows: State of Oaxaca, 

 Mexico, granites and gneisses; Chiapas and Guatemala, granites, 

 talc, and chloritic schists; Nicaragua and Honduras, fundamental 

 granite; Venezuela, granite from Puerto Cabello to Trinidad. Granitic 

 debris was found in Eocene sediments in Costa Rica and along Rio 

 Chagrcs in Panama by Hill. There is granite overlain by arkose 

 below the Upper Cretaceous near the city of Santa Clara, Cuba, and 

 marble and schists in the Isle of Pines. 



Paleozoic rocks of undertermined age occur in northern Sonora, 

 Mexico, and in Chiapas; in Guatemala there are formations of both 

 pre-Carboniferous and Carboniferous age; Mierisch reports Devonian 

 in northern Nicaragua; and Paleozoic rocks apparently are present 

 in Honduras. The rocks, largely serpentine, forming the proto-axis 

 of Cuba, and some of the formations in the Trinidad Mountains, 

 Cuba, may be of Paleozoic age, but there is no definite proof. 



Triassic deposits occur near Zacatecas, and perhaps at Miquehuana, 

 State of Tamaulipas, Mexico; the Todas Santos formation in Chiapas 

 and Guatemala is of Triassic age, and it appears, according to Mierisch, 



' Sapper, Carlos, La geografia flsica y la geclogia de la Feninsula de Yucatan, Mexico Instit. geolog. 

 Bol. No. 3, pp. 57, 6 pis., 1896. 

 » U. S. Geol. Survey Prof. Paper 71, 1912. 



