A Brief Review of Heat-Flow Studies in the Guaymas Basin, Gulf of California
K. Becker, A. T. Fisher, 1991. "A Brief Review of Heat-Flow Studies in the Guaymas Basin, Gulf of California", The Gulf and Peninsular Province of the Californias, J. Paul Dauphin, Bernd R. T. Simoneit
Download citation file:
The Guaymas Basin in the central Gulf of California is a young spreading center about 1.6-2.1 km deep, which is covered with a thick sequence of sediments. It provides an excellent location to investigate geothermal processes at a sedimented rift using conventional oceanographic heat-flow equipment. Rapid sediment accumulation at this site precludes the formation of “normal” oceanic crust by extrusion; instead, basaltic sills intrude semiconsolidated and unconsolidated sediments, expelling pore water and driving vigorous hydrothermal circulation. Deep-seated heat sources also drive longer-lived convection within and beneath the sediment cover.
The continuous sediment cover has allowed detailed and extensive mapping of the distribution of surface heat flow throughout the Guaymas Basin; more than 400 heat-flow measurements have been collected since 1959 in crust ranging in age from 0 to about 3 Ma. Away from the sites of crustal accretion, the background heat flow throughout the Guaymas Basin is about 180 ± 10 mW/m2. Within the two spreading centers of the basin, known as the northern and southern troughs, heat-flow values range from 0 to nearly 9 W/m2, and variations of two orders of magnitude occur over distances as short as a few hundred meters. Heat-flow patterns generally follow the northeast-southwest structural trend of the central troughs but are locally controlled by recent intrusive activity and associated hydrothermal circulation.