246 BULLETIN OF THE 



I preferred to examine the phenomena entirely de novo, so as to be 

 influenced by no preconceived hypotheses, and hence made no study 

 of these writei-s until my report was formulated. After outlining this 

 paper I examined this literature, and I hope that the present discussion 

 of the topographic and diastrophic phenomena will further advance the 

 ■work so well begun hy others. I am also glad to affirm, with a few 

 minor exceptions, the views of the structure set forth by these earlier 

 writers, and I would earnestly request those who read this paper to 

 consult them. 



I. ELEMENTARY GEOLOGIC STRUCTURE. 



The Pre-Tertiary, MetamorpJiic, and Igneous Foundation. — This is a 

 floor of ancient (certainly Pre-Tertiary) rocks, consisting of serpentine 

 and igneous material, mostly basic in aspect. These are exposed by 

 erosion at various points throughout the island, but, except in the 

 Santiago region, they seldom, if ever, form the rocks of the immediate 

 coast, although often found quite near it. Thej'^ now underlie most 

 of the island at no great de[)th, and are exposed in many drainage 

 cuts beneath the limestones. Wherever I have seen these rocks — at 

 Villa C'lara, Havana, and near Baracoa — they had once been covered 

 by the Tertiary limestones, but I cannot speak with certainty concern- 

 ing the province of Santiago de Cuba, where, according to Kimball, 

 traces of limestone as high as 2,300 feet are pi'eserved on the south side. 

 On the north side, opposite Santiago, they are certainly overlapped far 

 interiorward by the limestones. Some of the igneous and metamorphic 

 rocks of the Santiago region may be of later origin and intrusive 

 through the limestone, but generally throughout the island they have 

 been completely covered by the latter. No Post-Tertiary eruptive 

 sheets were seen hv me except one small dike which intrudes into the 

 greatly folded limestone near the water-works back of Havana. (See 

 Plate I. Fig. 3.) 



These older rocks consist of diorites, serpentines, schists, and rarely 

 granites, as reported from Santiago ; of serpentines, gi'eenstonc, porphyry, 

 and basic igneous rocks brought down by the rivers of the north side of 

 the east end of the island ; of serpentine and metamorphic rocks with little 

 quartz, as seen underneath tlie limestone in the vicinity of Villa Clara ; 

 and of serpentine, tuffs, and old volcanic material, as back of Havana. 



The rare presence of eruptives and of sedimentaries older than C're- 



