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 Radiolites, which would clearly indicate the occur- 
rence of Cretaceous deposits in Cuba.? 
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 mto schists 
in places, as may be seen nine miles north of Villa Clara, where the 
anticlinal rocks overlying a vast intrusive bed of asphaltum 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 difficult, owing to the 
folding, induration, and erosion, the thick 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, ete., por Don Manuel Fernan- 
dez de Castro, Madrid, 1884, p. 6. 
