The very early thermal state of Terra Cimmeria: Implications for magnetic carriers in the crust of Mars

Large areas of shongly magnetized crust are located inTerra Cimmeria and Terra Sirenum, in the south ern hiehlands of Mars. the older terrains on the rilanet The tvuical deuth to the base of the maenetized crustal eeotherms consistent with a orevious estimation o í the effective elastic thickness of the Iitho sphere, and with crustal abundanres of heat-producing elements based on swfare measurements performed by the Mars Odyssey Gamma Ray Spectrometer. The results suggest that, at the time of formation of the maenetized terrains surface fwhich have a minimum aee of 4.1 Gai. Cune d e ~ t h s for magnetite and hematite were shallowet and similar, respectively, than the typical depth to the b z e of the magnetized layer. This implies that hematite is an important (if not dominant) contributor to the magnetization of the martian must. However, an early warm climate would enhance the chance of magnetite to be a iignificant. even dominant, magnetization carrier in the lower portion of the magneticlayer.