Geological evolution of the Caribbean region; A plate-tectonic perspective
This chapter examines the geologic evolution of the Caribbean region from a plate-tectonic perspective, and is composed of three major parts. First, some primary tectonic constraints on plate-tectonic models of Caribbean evolution are defined and reviewed. These constraints include: (1) the platekinematic framework: the spatial relationships of the plates through time, derived from an initial reconstruction and the subsequent relative motions of the North American, African, South American, and FarallÃ³n plates, which encompass the Caribbean area; and (2) the following plate-tectonic elements: (a) the polarity and timing of subduction (magmatic activity) of arcs (arcs = magmatic belts), (b) the age of formation (magmatic crystallization) and of emplacement of pieces of oceanic crust preserved in thrust belts, (c) the timing and vergence of thrusting within known Caribbean collision zones, (d) the paleogeographic significance of the YucatÃ¡n Basin, Grenada Basin, and Cayman Trough, and (e) the development of the northern and southern Caribbean plate boundary zones.
Second, in tabular form, twelve published models of the plate-tectonic evolution of the Gulf of Mexico and Caribbean are examined by outlining the implications of each for seventeen subregions, by highlighting alternate interpretations of the geologic history of each subregion, and by presenting arguments for choosing among the alternatives. Third, a new model of Caribbean evolution is developed by integrating the Caribbean platetectonic elements, defined earlier, into an accurate plate-kinematic framework. The new model is presented on eight plate-boundary maps with accompanying descriptions (see accompanying plate).