G02 BULLETIN" 103, UNITED STATES NATIONAL MUSEUM. 



Cuban trend. The structural 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 Ridge. — 'The Honduran Province in 

 Central America is dominated by tectonic lines extending from south- 

 west to northeast, of which the Telusa Mountains are representative. 

 A line from the Gulf of Honduras along Motagua River to a point 

 north of Jalapa, thence southwest to the Pacific coast, may be taken 

 as the northern boundary and Rio San Juan and the southern side 

 of Lake Nicaragua as the southern boundary. 



From the northeast coast of Honduras and Nicaragua a great sub- 

 marine plateau continues with depths of less than 1,000 fathoms to 

 Jamaica. Above it rise numerous banks and keys and along its 

 course are Thunder Knoll, Rosalind, Seranilla, and Pedro banks 

 between the continental shore and Jamaica. 



The principal old tectonic lines of Jamaica trend northwest to 

 southeast. As these are parallel to the shore northwest of Cape 

 Gracias a Dios and to the northeast edge of Mosquito Bank, there 

 are evidently cross tectonic lines nearly at right angles to each other 

 in this ridge. 



A submarine ridge extends from the east end of Jamaica some 45 

 miles and overlaps on the south side a ridge which protrudes west- 

 ward from the west end of Haiti. The two ridges, however, do not 

 connect but are separated by water over 1,000 fathoms deep. The 

 ridge representing an eastward submarine continuation of Jamaica 

 indicates a third tectonic line in that island. The last-mentioned 

 line nearly parallels the Bartlett deep, which lies to the north. The 

 submarine slopes to the southeast are toward the bottom of the 

 Caribbean basin. 



Sa. Haiti (southern part), Porto Rico, and the Virgin Islands. — The 

 political division of Haiti designated Sud is dominated by east and 

 west trending mountains, which parallel in direction the east and 

 west axis of Jamaica. As the maximum depth between Haiti and 

 Porto Rico is about 318 fathoms, they rise from a common, not greatly 

 submerged bank. (See statement on preceding page in regard to 

 considering Haiti as a separate Province.) 



The main mountain mass of Porto Rico, the Sierra Central, the 

 maximum altitude of which is 3,750 feet at El Yunque, trends east 

 and west, paralleling in direction Sud, Haiti. There is coincidence . 



