Geographic Character: West Indies. 127 
coast. Sagua la Grande, the North and South Jatibonico, the Cuyaguateje, 
Zaza, Agabama and Guanabana are also notable streams. The distinct types 
of relief, then, include regions of high mountains, low hills dissected plateaus, 
level plains, valleys and coastal swamps. The southern coast produces the 
extensive cienaga, or swamp, known as the Zapata on the coast opposite 
Matanzas and continues out into the sea toward the Isle of Pines, ‚which oc- 
cupies the concave depression of the south coast of the island. 
The island from a geologic standpoint consists of an older basement of 
pre-Tertiary sedimentary rocks in which fossils of Cretaceous and probably 
Jurassic age occur. Above this are littoral beds, then a thickness of white 
limestones, as distinguished from true reef rock of late Eocene and Oligocene 
age. The island was reclaimed from the sea and assumed its present physio- 
"graphic condition by the great mountain uplift of late Tertiary time, following 
the deposition of the oceanic limestones. Subsidences and elevations occurred 
in the Pliocene and Pleistocene, which altered the coastal borders, producing 
eroded cliffs and elevated reef rock. 
e. Jamaica. 
The island of Jamaica is an elevated portion of the submerged bank which 
extends southwestward from Santo Domingo. Between this island and Cuba 
occurs the eastern lobe of the great Bartlett Deep, three thousand fathoms. 
The relief is mountainous, and at a distance from the east the island presents 
a group of mountain summits rising above the sea in a confused mass without 
regular ridges or secondary types of relief. Upon a nearer approach, four 
distinct physiographic types are recognizable.. These are (1) the interior 
mountain ranges constituting the nucleus of the island; (2) an elevated lime- 
stone plateau, which surrounds the mountains and ends abruptly toward the 
sea; (3) the coastal cliffs, or back coast border of the oceanic margin of the 
plateau; and (4) a series of low level coastal plains around the edge of the 
island, between the sea and the back coast border. 
he plateau is a shelf built out from the mountain masses through which 
the higher summits project. In the west of the islands, where the limestone 
becomes dominant, occasional views of the buried mountain formations may 
be seen, where running water has etched away the superficial limestone 
deposits. The Blue Mountain ridge found in the eastern interior dominates 
the topography of that end of the island. It extends in an irregular manner 
one-third the length of the island culminating in Blue Mountain Peak, 7360 feet 
(2240 m) high. The elevation of the range decreases west of this peak, until 
the mountain rocks sink below the limestone hills. West of St. Catherine Peak, 
5036 feet (1530 m), the main range forks, the southern branch continuing 
through St. Andrew Parish. The mountains consist of loosely consolidated 
shales, conglomerates and clays with occasional limestone beds and dikes of 
igneous rock. The old formations are seen in some of the great central valleys, 
where they are exposed by the wearing away of the limestone. 
