/4 J. W. SPENCER — GEOGRAPHICAL EVOLUTION OP CUBA. 



road. There are here gray and buff sandstones, containing shells of the genera 

 Exogyra, Osirea and Inoceramus ; also at Limones, a farm in a little valley farther 

 up, there are beds of dark and gray sandstone holding shells of the genera Ostrca 

 and Inoceramus. The sandstones are accompanied bj'^ a brown conglomerate liold- 

 ing pebbles of feldspar, porphyry and diorite. The limestones of the Constancia 

 landing and Concepcion estate (ravine near the landing) ... lie along the 

 eastern side of the arenaceous band seen at the Constancia buildings and the ferry. 

 They are mostly of a pale buff tint, and are rejdete with organic remains, being in 

 fact Hippurite limestone. This type of shell {Hippurites) of several species, with 

 CaprineUa and Caproiina (?) abound in tiiem, and they also contain corals and sev- 

 eral kinds of univalve and bivalve shells, among which are a large Olini, a Conns, 

 an oyster of the type Ostrea cristata, Echini and sponges. 



"One feature of remark in the Cretaceous rocks of the district of Cienfuegos is 

 the evidence they give of the extent to which the hardening process has gone on 

 in them. This condition of the beds is not limited to the district on the Damuji 

 which I have spoken of, but characterizes them over a large area, for in hardness 

 and coherence thev resemble rocks of the Carboniferous." 



Mr Mathew also emphasizes the stupendous changes of terrestrial 

 movements in the later geologic times throughout the West Indian 

 region. 



Havana region. — In the vicinity of Havana and eastward, denudation 

 has removed the Tertiar}" formations and exposed large areas of the same 

 strata as those seen at Trinidad and ("ienfuegos. Whether all of the 



limestones, such as those described, 

 belong to the Cretaceous or not is 

 an unsettled question, one which 

 k^alterain, who has done more work 

 in the Havana region than any 

 other geologist, has not l)een al)le 

 to answer. The rocks seen in the 

 Havana district appear less crys- 

 talline than those observed on the 

 southern coast, but the strata are much more faulted and jointed than 

 farther southeast. 



In the Havana district there is a lower calcareous glauconitic sand 

 resting on the serpentine and associated rocks. Overlying the sands 

 there is a calcareo-magnesian marl or Ihnestone which in places is so 

 faulted and jointed as to make it im])ossible to determine the dip of the 

 strata (see A, figure 3). In one locality the di]) is clearly 70° south, 30° 

 west, but it is difficult to determine whether the southwestern or north- 

 eastern dip prevails. From the section of these rocks seen along the 

 railway west of Havana, it would appear that these accumulations, 

 probably Cretaceous, are very thick. 



Figure 3.— A Sectioti along Raihvay on the east 

 Side 0/ Havana Bay. 



A = jointed and broken limestone \ C, C = 

 beds of the sandstones faulted into positions 

 between beds of marls = D, D. 



