Abstract

The eastern Caribbean margin has been defined as a typical Atlantic type B subduction zone; however, data from earthquake hypocenters, seismic refraction, seismic reflection, and early gravity suggest that the Atlantic slab has different subduction styles. Regional data set of Bouguer gravity anomalies were used to evaluate the real tectonic configuration of the Atlantic slab under the Caribbean plate. Additionally, three gravity profiles, constrained by previous seismic, gravity, and well data, were modeled to define the slab behavior. Results from gravity analysis and modeling show a slab fragmented into three subduction blocks separated by tear faults with different angles. North of the Lesser Antilles arc, the subducting angle is greater than in the south where sediments of the Barbados accretionary prism produce a load that bends the Atlantic lithosphere decreasing slab’s subduction angle. Finally, the execution of more detailed seismological studies is suggested to evaluate tear faults tectonic characteristics and the implications of the Barracuda and Tiburon ridges incipient subduction on the Atlantic slab behavior.