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The Barbados Ridge complex lies east of the Lesser Antilles volcanic arc along the eastern margin of the Caribbean Plate. The complex dates in part from the Eocene, and elements of the arc system have been dated as Late Cretaceous and Late Jurassic, although most of the volcanic rocks date from the Tertiary, particularly the latter part. It is probable that the arc system was moved a considerable distance eastward with respect to North and South America during the Tertiary. The accretionary complex can be divided into zones running parallel to the arc, starting with a zone of initial accretion at the front of the complex where sediment is stripped from the ocean floor and the rate of deformation is greatest. This zone passes into one of stabilization where the deformation rate is generally lower, although there are localized zones of more active tectonics where the generally mildly deformed overlying blanket of sediment is significant disturbed. Supracomplex sedimentary basins that are locally very thick are developed in the southern part of the complex. The Barbados Ridge Uplift containing the island of Barbados lies at the western edge of the complex; between it and the volcanic arc lies a large forearc basin comprising the Tobago Trough and Lesser Antilles Trough. There are major longitudinal variations in the complex that are broadly related to the northward decrease in sediment thickness away from terrigenous sources in South America and that are locally controlled by ridges in the oceanic igneous crust passing beneath the complex. An important feature of the complex is the underthrusting of undeformed sedimentary horizons at least 80 km westward beneath the accretionary wedge. This underthrusting is facilitated by very high pore fluid pressures, which are presumably also related to the large number of mud diapirs in the southern part of the complex. The style of deformation is dominantly one of thrusting, although folding occurs in association. The size of deformational structures is directly related to the thickness of the accreted layer lying above the décollement, which separates it from the undeformed sediment beneath. The geology of Barbados and seismic stratigraphy show that the complex has had an episodic rather than a smoothly evolutionary or steady-state history.

In this paper we attempt to reconstruct the general history of the Alpine-Mediterranean realm on the basis of geological crosssections onland and offshore, general mapping of the basins and the main structural units of the Mediterranean area, and geophysical data. The history of the Alpine-Mediterranean realm is related to the plate movements of Europe and Africa and associated with the opening of the Atlantic. After a first stage with a broad oceanic domain (Tethys), the opening of a proto-eastern Mediterranean and the formation of active margins south of Europe modified the physiography until the stage of continental collision. The western and eastern Mediterranean basins differ. The western basins are very young: Oligocene-Miocene episutural and intracontinental marginal basins, recently rejuvenated (Tyrrhenian Sea) and always part of the Alpine orogenic belt. The eastern basins are remnants of a former much larger Mesozoic basin south of the still active Alpine belt. The Cyprus, Aegean, and Calabrian arcs are described successively. Diagrammatic sections and schematic maps show this Cenozoic evolution and a speculative history is presented.