618 T. W. VAUGHAN— GEOLOGIC HISTORY OF CENTRAL AMERICA 



nated by east and west tectonic lines, and has been called the Gnatemala- 

 Chiapas Plateau by Tower. '^ 



7. Cuba: This province is coincident with Cuba and its submarine 

 continuation, the Cayman Eidge. At least four subdivisions should be 

 recognized: (1) The Isle of Pines, which is composed of mountains of 

 schists and marbles with piedmont plains and marsh, separated from the 

 main island by water less than ten fathoms deep. (2) Organos Moun- 

 tains of Pinar del Eio and the accompanying piedmont plains. The 

 1,000-fathom curve is less than 20 miles off the north shore. (3) Central 

 Cuba, from the east end of Organos Mountain to Cauto Eiver, is mostly 

 a plain broken by some hills of serpentine and granite, and in Santa 

 Clara Province, near Trinidad, mountains reported to be composed of 

 Paleozoic sediments attain an altitude of about 2,000 feet. (4) Sierra 

 Maestra and Cayman Eidge. This subprovince lies between the Cauto 

 Valley and the south shore and is continued westward as the submarine 

 Cayman Eidge, along the axis of which only the Cayman Islands project 

 above water level. The axial trend is nearly east and west between Cabo 

 Cruz, Cuba, and Little Cayman, whence it curves to the southwest and 

 pitches toward the head of the Gulf of Honduras, which is an area of 

 depression. Between the Caymans and the Isle of Pines the depth of 

 water exceeds 1,000 fathoms, while the Bartlett Deep to the south, sepa- 

 rating Cuba and Jamaica, exceeds 3,000 fathoms in depth. 



7a. Haiti, northern part: The Island of Haiti lies at the convergence 

 of the trend of the axis of the central subprovince of Cuba and the Hon- 

 duras-Jamaican axis. The dividing line in Haiti is from Port au Prince 

 to Ocoa Bay. The area south of this line belongs to a Jamaican axis, 

 while that to the north belongs to the central Cuban trend. The struc- 

 tural axes of the mountains in the northern and northeastern part of 

 Haiti are from northwest to southeast and are parallel to the axis of 

 elongation of Cuba from the Sierra Maestra to Santa Clara. In Cuba 

 this trend is cut diagonally by the axis of the Sierra Maestra, which is 

 bounded on the south by a tremendous fault-scarp. Previous to this 

 faulting it seems that central Cuba and Haiti formed parts of the same 

 land area. The Island of Haiti might be treated as separate from Cuba 

 and Jamaica, but lying at the intersection of two tectonic trends. 



8. Honduras and the Jamaican Eidge: The Honduran Province in 

 Central America is dominated by tectonic lines extending from southwest 

 to northeast, of which Telusa Mountains are representative. A line from 

 the Gulf of Honduras along Motagua Eiver to a point north of Jalapa, 



^ W. L. Tower : Investigation of evolution in chrysomelid beetles of the genus Leptino- 

 tarsa: Carnegie Inst. Washington, Pub. No. 48, 190G, p. 50. 



