Caribbean Geology The oldest land areas of the modern Caribbean are at the extreme ends of the arc of islands in Cuba and Trinidad. The Greater Antillean islands have all had a somewhat similar geological history but they differ from one another in the distribution, form and erosion patterns of the limestones deposited during several phases of submergence and uplift through the Tertiary period and Pleistocene. Apart from sporadic unions between islands now separated by shallow seas, as within the Bahamas, Virgin Islands or Grenadines (as groups), the other islands have always been separate from one another.
The Virgin Islands are peaks of a drowned mountain range created by volcanic activity in the Cretaceous. he northern part of the Lesser Antilles comprises two more or less parallel arcs of islands. The irregular outer arc stretches from Anguilla to Antigua, the “Limestone Caribbees” (Harris 1965), and extends to include Grande-Terre of Guadeloupe, La Desirade and Marie Galante at the southernmost end. The complex geological history is represented by volcanic and sedimentary strata of Oligocene age, ranging to Pleistocene coral limestone and alluvium.
THE CARIBBEAN is a geologically complex region that displays a variety of plate boundary interactions including subduction in the Lesser Antilles and Central America, transcurrent (strike-slip) motions on the northern and southern boundaries, and sea floor spreading in the Cayman Trough. The central Caribbean is a lithospheric plate consisting mainly of an anomalously thick, oceanic plateau situated between two major continental regions and therein lies its geological importanceThe western boundary comprises Central America and the Isthmus of Panama, and the astern limits are defined by the Lesser Antilles archipelago. Within these boundaries there are several deeper water regions; the Yucatan Basin, the Cayman Trough, the Colombian Basin, the Venezuelan Basin and the Grenada Basin. These are separated by several more or less linear ridges and rises; by the Cayman Ridge, the Nicaraguan Rise, the Beata Ridge and the Aves Ridge, respectively. The physiographic units correspond in part to the different crustal provinces that make up the Caribbean and in part to the active tectonic elements that make up the present Caribbean Plate.