190 CUBA AND POltTO RICO 



When one considers the softness of the material, and how 

 rapidly degradation is going on and has gone on, he can 

 but conclude thai the mountains were once of much 

 greater altitude and extent. There is no reason why 

 their summits in times past may not have extended as 

 high as their kindred in the Sierra Maestra of Cuba, over 

 eight thousand feet, or in Santo Domingo, over ten thou- 

 sand feet. 



The old Blue Mountain rocks reajDpear in many places 

 in the great central valleys of St.-Thomas-in-the-Vale, 

 Clarendon Parish, Great Eiver, and elsewhere to the west, 

 where the later crust of the wdiite-limestone plateau has 

 been worn away. They are also seen in the face of the 

 back-coast bluffs along the western half of the north side 

 of the island, below the limestone and above the narrow 

 coastal benches. They are all parts of the same grand 

 Antillean system which we have previously described. 



The western two thirds of the island is occupied by the 

 great white-limestone plateau, a wonderful and diversified 

 region of hills, valleys, and exquisite landscapes. This 

 feature, a later addition to the geologic architecture, is a 

 dissected plain, which has been carved and cut into a 

 thousand hills, pitted with wonderful sink-holes and 

 valleys, and covered with exquisite vegetation. Its main 

 area stands like a shoulder some two thousand feet high, 

 extending westward from the still higher sierras, although 

 a narrow belt or collar of it completely encircles the east- 

 ern end of the island. 



As a whole, the profile of the plateau, could the irregu- 

 larities of erosion be eliminated, would be a very gentle 

 arch sloping north and south toward the adjacent seas. 

 The curves of this arch, if continued, would not meet the 

 sea at the present margin of the land, but would intercept 

 it quite a distance beyond the shores, indicating that the 

 former borders, now restricted by the agencies which have 

 sculptured the steep margins of the plateau, were once 

 much more extensive. 



