248 BULLETIN OF THE 



upon what ground, except stratigraphic position, I cannot say. He 

 reports other Mesozoic sedimentaries at both ends of the island, together 

 with Ammonites and RadioUtes, which would clearly indicate the occur- 

 rence of Cretaceous deposits in Ciiba.^ 



The Esperanza clays with plants disclose a Pre-Tertiary land accom- 

 panied by erosion, but its area and extent I cannot interpret. There 

 are indications that these clays have been metamorphosed into schists 

 in places, as may he seen nine miles north of Villa Clara, where the 

 anticlinal rocks overlying a vast intrusive bed of asphaltiim show many 

 evidences of transition. This idea, however, is at present merely a 

 suggestion. 



Formations of the Tertiary Subsidence. — In strong contrast with the 

 Esperanza clays and the older metamorphic floor are the Tertiary and 

 later limestones which cover them, and which are the predominant geo- 

 logic feature of Cuba. These certainly once extended over all the island, 

 with the possible exception of a small portion of the high mountainous 

 region before mentioned, in the vicinity of Santiago de Cuba. They 

 still occupy by far the greater portion of the whole area. The study 

 and classification of the limestone complex is difhcult, owing to the 

 folding, induration, and erosion, the thicl< covering in places of residual 

 soil and vegetation, the universal alteration they have undergone through 

 solution and internal changes, and the general concealment by tufaceous 

 incrustation of well defined stratification planes and partings. The lime- 

 stones are clearly divisible into the two general categories of the newer 

 and the older, or basal. The former consist mostly of unfolded rocks of 

 undoubted coral reef origin, and occur on the lower levels adjacent to 

 the coast, while the latter, if of coral reef origin, have- lost all character- 

 istic features, of rocks of such origin, are undulated and folded, and 

 constitute the uplands and high coastal scarps against and around which 

 the later coral rock grew. 



The more ancient limestones nearly everywhere constitute the upland 

 of the island, and by alteration and underground decay have lost their 

 coralline structure, if they ever possessed it. These, so far as my 

 observations extended, constitute all the limestones of the island above 

 an altitude of one hundred feet. These older limestones are diverse in 

 texture and composition. Where good exposures are obtainable, they 

 usually exhibit well defined stratification and separation planes, never 

 seen in the undoubted reef rock, and sometimes alternate with more 



1 Pruebas Paleontologicas de que la Isla de Cuba, etc., por Don Manuel Fernan- 

 dez de Castro, Madrid, 1884, p. 6. 



