National Geographic : 1898 May
CUBA flanked below 2,000 feet by horizontal benches or terraces, which are the result of regional elevations and base-leveling after the last period of mountain-making in Miocene time. The Antil lean uplift may be compared to an inverted, elongated canoe, the highest and central part of which is in the region adjacent to the Windward passage. Thus it is that the higher peaks occur in Haiti, eastern Cuba, and eastern Jamaica, while the arching crest line descends toward the western part of the two latter islands and, on the east, toward Porto Rico. The higher mountains are composed of non-calcareous clay conglomerate and igneous rock, the debris of unknown lands of pre-Tertiary time, which, with the exception of a few restricted points, were buried, during a profound subsidence in early Tertiary time, be neath a vast accumulation of calcareous oceanic sediments now composing the white limestones which constitute the chief for mations of the islands, and which were, together with the pre ceding formations, elevated into their present position at the close of the Tertiary period.* The mountains above 2,000 feet are composed of the older non-calcareous formations and the border ing plateaus of limestone, resulting in two distinct and contrast ing types of soil throughout the Antilles. STRATEGIC AND COMMERCIAL POSITION In area, in natural resources, in the number and character of its inhabitants, in position as regards proximity to the American and Mexican seaboards, strategically Cuba is by far the most im portant of the Great Antilles. It is very near the center of the great American Mediterranean, separating the Gulf of Mexico from the Caribbean sea, and in close proximity to our southern * The general geology of the island, while not discussed in this article, is well shown in many of the illustrations. It may be briefly stated as consisting of an older base ment of pre-Tertiary sedimentary rocks, in which Cretaceous and probably Jurassic fossils have been found. Above this there are, first, littoral beds composed of terrig enous material, and then a great thickness of white limestones consisting of organ ically derived oceanic material, as distinguished from true reef rock of late Eocene and Oligocene age. The island was reclaimed from the sea and assumed its present relief by a great mountain-making movement in late Tertiary time, succeeding the deposition of these limestones. In later epochs, Pliocene and Pleistocene, the island underwent a series of epeirogenic subsidences and elevations which affected the coastal borders, producing the wave-cut cliffs and a margin of elevated reef rock which borders the coast in many places, as can be recognized in the illustrations of the cities of Habana and Baracoa. So far as its history is known, the island has never been con nected with the American mainland, although such has frequently been asserted to be the case. These assertions have been based upon the erroneous identification of cer tain vertebrate animal remains. There are no traces in the animal life of Cuba, past or present, which justify this conclusion. Some of the crystalline rocks may be ancient, but most of them are mid-Tertiary in age.