SAND TRANSPORT; A SOURCE OF MINERAL ALTERATION ON MARS

Introduction: Here we present a possible new formation mechanism for the reddish Martian dust or specifically the oxidation process which has led to the presence of a reddish iron oxide in Martian dust which is presumed to be hematite. This mechanism involves the wind induced erosion of sand (for example basaltic material). Such basaltic sand forms are observed widely across the Martian surface. In the laboratory experiments presented here simulation of silicate sand erosion (specifically quartz sand) together with magnetite (observed in basaltic Martian material) leads to oxidization of the magnetite and the formation of hematite. Motivation: The magnetic properties experiments upon the NASA Mars MER mission consisted of capturing windblown dust from suspension in such quantities to allow mineralogical analysis [1]. This study concluded that the Martian (airborne) dust essentially resembled (grey) basaltic regolith though with a highly oxidized (reddish) iron oxide phase, possibly nanophase. This leads to the assumption that the Martian dust is an erosion product of the basaltic sand, though the oxidization process remains speculative and has motivated further study for possible mechanisms.