204 E. T. Hill— Tertiary and later 



II. 



Geologic History recorded by the Topography. 



Having reviewed the fundamental rock structure upon 

 which the sculpture of the land is dependent, we can now con- 

 sider the general topograph} 7 and its evolution. It is neither 

 necessary nor possible to give a detailed description of the 

 minute geography of Cuba, except so much as relates to the 

 genesis of the island. Its shape and outlines have been de- 

 scribed by various writers, notably Humboldt, Sagra and 

 Eeclus, and I shall only touch upon those details or generali- 

 ties which will help elucidate its geologic history. 



The Santiago coast is exceedingly mountainous, and is sup- 

 posed in some way to be genetically connected with the moun- 

 tain systems of the other Antilles. Concerning the composi- 

 tion, age, and topography of the mountain ranges we know 

 but little except what has been told by other writers, to the 

 effect that they approximately extend in an east-and-west direc- 

 tion, and tower far above the levels of the remaining portion 

 of the island and occupy a very narrow strip close to the 

 ocean's margin. Extending away to the north and west from 

 this nucleal elevation is the main body of Cuba which is pri- 

 marily a great limestone plateau deeply eroded and leveled, 

 without any sharply defined central axis of higher elevation 

 except the diverging headwater drainage flowing into the 

 opposing seas. The highest elevations do not occur in a con- 

 tinuous ridge but are irregularly dispersed as if they were pro- 

 duced by the degradation of an elevated plateau resulting in 

 the alternation of plains and irregular chains of hills, the 

 latter often being nearer the margin than the center, and sel- 

 dom over 2,000 feet in altitude. 



The eminences called mountains seen by me, with the ex- 

 ception of the Sierra Maestra and kindred ranges of the San- 

 tiago coast, are mostly either (1) the direct remnants of the 

 old limestone covering carved out by circumscribing erosion, 

 or (2) inequalities in the ancient metamorphic floor from which 

 the limestone has been denuded. The mountains of the former 

 kind can be placed in two general classes according to their 

 altitude and degree of erosion. First are the high limestone 

 peaks, mesas, and ridges with a present altitude of from 1,000 

 to 2,000 feet. The Sierra Jnnki of Baracoa, the Fan de 

 Matanzas, and the Tetas de Managua, are examples of isolated 

 peaks, standing close to the north shore of the Island. Each 

 of these is surrounded by deep cut drainage valleys and is 

 many miles away from any masses of land of similar altitude. 

 Their summits are made of the subhorizontal strata of old 

 limestone, while the base of at least one, the Sierra Junki, con- 



