Heat flow and thermal regime in the Guaymas Basin, Gulf of California: Estimates of conductive and advective heat transport #

Abstract #

This dataset presents heat flow estimates from eight drilling sites in the Guaymas Basin, Gulf of California, collected during the International Ocean Discovery Program (IODP) Expedition 385. The data capture the thermal regime of a sediment-filled, magmatically active rift basin where sills intrude into organic-rich sediments. Sedimentation-corrected heat flow values range from 119 to 221 mW m⁻² across the basin and rise dramatically to 257–1003 mW m⁻² at a young sill complex known as Ringvent. Thermal and hydrological modeling indicates that Ringvent is currently cooling via hydrothermal circulation, with discharge velocities of 10–200 mm yr⁻¹. The results provide critical insights into sill emplacement, transient heat transfer, and crustal evolution in young rift environments.

Methods #

Heat flow measurements were obtained at eight drilling sites across the Guaymas Basin during IODP Expedition 385. These sites were selected to capture a range of geological settings, including background basin conditions and a recently emplaced off-axis sill (Ringvent).

Sediment temperature profiles were acquired using in-situ probes during drilling, and thermal gradients were combined with sediment thermal conductivity to compute heat flow. Corrections were applied for sedimentation effects, particularly in rapidly accumulating basins.

Other #

The Guaymas Basin is a young, tectonically active rift basin in the Gulf of California, characterized by rapid sedimentation, magmatic intrusions, and organic-rich depositional environments. Unlike typical mid-ocean ridges, the basin features thick sedimentary cover into which basaltic sills intrude, providing a unique opportunity to study the coupling between magmatism, sedimentation, and hydrothermal processes.