Is the primordial crust of Mars magnetized?

► Impacts creating craters larger than 200 km can demagnetize the entire crust of Mars. ► Craters and QCDS larger than 200 km in Tempe Terra have no magnetic signatures. ► The crust underlying the Tempe Terra on Mars is not appreciably magnetized. ► No strong core dynamo existed within the first about 100 Myr of Mars history.