Heat flow from eastern Panama and northwestern Colombia

Heat flows were determined at 12 sites in four distinct areas between longitude 77° and 80°W in eastern Panama and northwestern Colombia. Evidently, most of the region is underlain by mafic oceanic crust so that the crustal radiogenic component of heat flow is very small (∼ 0.1 μcal cm⁻² sec⁻¹). Low heat-flow values (∼ 0.7 μcal cm⁻² sec⁻¹) in northwestern Colombia may reflect thermal transients associated with shallow subduction. The normal values (∼ 1) at about 78°W are consistent with the mean heat flow from the western Caribbean and the Gulf of Mexico. At 80°W, a fairly high value of 1.8 may define the easterly limit of thermal transients due to Cenozoic volcanic activity in Central America.