Evidence for a differentiated crust in Solis Planum, Mars, from lithospheric strength and heat flow

Two independent sets of heat flow estimates provide constraints on the Hesperian-era surface and mantle heat flows, and the thickness of the heat-producing elements (HPE)-enriched upper crust, in the Solis Planum region of Mars. The calculations, which use the concentration of uppermost crust heat sources deduced from orbital gamma ray spectroscopy and soils geochemistry, are based on the effective elastic thickness of the lithosphere and the minimum depth of faults underlying winkle ridges. We find that, for the majority of analyzed settings, the HPE-enriched crust is thinner than the whole crust thickness in this region (∼65 km). Thus, our results strongly support a differentiated martian crust.