Post-middle Eocene Stratigraphy
At the close of the middle Eocene, most of the strong orogenic deformation in Cuba had occurred, and the general distribution of the pre–upper Eocene structures and stratigraphic units was essentially as it is now. The younger Tertiary sediments began to accumulate over the now-essentially inactive, largely peneplained, submarine mountain chain, reflecting some large-scale deformation that included folding and faulting.
The overall movements during the remainder of the Tertiary have been of a slow, continuous uplift, with much of Cuba emerging by the Miocene. The younger Tertiary sedimentation consisted mostly of the filling of topographic depressions, although erosion of uplifts and filling of subsiding areas also occurred.
It should be noted that Gulf Oil, with the exception of a few areas in central Cuba, did little work on the younger Tertiary; therefore, much of the following is derived from published information, namely, Iturralde-Vinent (1977, 1988), Jakus (1983), and Fernandez et al. (1987).
As shown in Figure 148, the post–middle Eocene will be described according to the following areas:
Northern coast = Havana to Oriente Provinces
Southwestern basin = Los Palacios Basin, Habana-Matanzas, and western Las Villas
South-central basin = Central Depression (Gulf of Ana Maria)
Southeastern basins = Guanacayabo-Nipe Basin, central syncline, Guantanamo depression, and southern coast (only the stratigraphic unit of the Oriente southern coast will be listed).
A characteristic of most upper Eocene and later sediments is their richness in fossils, mostly large and small
Figures & Tables
The geology of Cuba has been a challenge to geologists because of features such as the presence of well-preserved Jurassic ammonites, the rich Tertiary foraminiferal faunas (including remarkable Paleogene orbitoids), the gigantic Upper Cretaceous rudistids, the spectacular limestone Mogotes of Pinar del Rio, the extensive outcrops of ultrabasic igneous rocks, the chromite and manganese deposits, and the extraordinary structural complexity. In addition to these features, the numerous petroleum seeps, many of them coming out of basic igneous rock, have attracted much attention.
It is interesting to read early papers by reputable geologists such as E. DeGoyler (1918), J. W. Lewis (1932), or R. H. Palmer (1945), and to realize how little was known or understood about the geology of the southern portion of the North American continent in the early part of the 20th century.
Much early understanding of the geology of Cuba resulted from a series of studies conducted between 1936 and 1946 by the University of Utrecht, Holland, under the direction of L. M. R. Rutten. Some resultant publications are Rutten (1936), MacGillavry (1937), Thiadens (1937a, b), Vermut (1937), van Wessen (1943), Keijzer (1945), Hermes (1945), and De Vletter (1946). These authors outlined the components of a classic geosyncline. Between the late 1930s and late 1950s, Cuban geologists and paleontologists, such as P. R. Ortega y Ros, J. Broderman, P. Bermudez, and J. F. Albear, published several articles about the island’s geology.
The search for oil has contributed significantly to the present understanding of the island’s geology.