A new hypothesis for the origin and redistribution of sulfates in the equatorial region of western Mars

The formation of sulfates on Mars has been under debate since they were identified by several Mars missions starting from the 1970s. We propose that sulfates formed as evaporites in enclosed standing bodies of water in the Valles Marineris area following the early alteration of Martian basaltic crust, were then elevated by the Tharsis uplift, and transported together with rock materials to Meridiani Planum by periodic outbursts of water, where they were deposited as sediments. The proposed model comprehensively addresses all forms of sulfate occurrences near the equator in the western Martian hemisphere and relates it to physiographic processes (volcanic, tectonic and sedimentary) affecting the Martian surface.