HEAT-FLOW, TECTONICS, AND FLUID CIRCULATION AT THE TOE OF THE BARBADOS RIDGE ACCRETIONARY PRISM

Detailed patterns of near surface tectonics and heat flow were investigated at two locations at the toe of the Barbados Ridge accretionary prism. At the two locations, in the thickly sedimented southern portion of the prism near 12°20′N and in the northern area drilled during Ocean Drilling Program (ODP) Leg 110 near 15°32′N, relative highs of heat flow were associated with zones of thrusting. We attribute them to upward advection of water rising from the decollement along faults through the sediments. In the ODP area, a significant heating plate effect from warm fluids flowing along the decollement and thrusts is required to account for the high regional heat flow. This effect implies high rates of fluid flow at the decollement, which can only be non-steady state or would require massive lateral transport of fluids along strike. -Authors