Heat flow in the Caribbean and Gulf of Mexico

Abstract

Eighty-seven new heat-flow values have been obtained in the Caribbean Sea and the Gulf of Mexico. Values in the Caribbean are, in general, uniform; only 5 of the 59 existing values lie outside the range 1–2 μcal cm−2 sec−1. Above-average heat flow is found in the area of the Cayman trough and the Yucatan basin. The excess flux may represent energy released during shear at the boundary between the Caribbean and Atlantic crustal plates. Resolution of the heat-flow pattern in the area of the Antilles Island arc is inhibited by too few values, some of which are of low reliability; below-average heat flow is found east of the arc and above-average heat flow west of it. The average heat flow in the Venezuelan basin is nearly the same as the average of all ocean basins. In the Colombia basin, heat-flow values trend from below average in the east to above average in the west. Through most of the Gulf of Mexico, the heat flow is uniformly low. A decrease of temperature gradient with depth in the sediment is characteristic of most of the Gulf measurements, and is not completely accounted for by known processes. The area of knolls, which includes the Sigsbee knolls, has uniformly high heat flow, 2.1 μcal cm−2 sec−1, which supports the hypothesis that the area is underlain by salt structures.