An explosive volcanic origin identified for dark sand in Aeolis Dorsa, Mars

Abstract Dark, windblown (eolian) sand on Mars has produced significant geologic effects throughout Martian history. Although local and regional sources have been identified, a primary origin, or genesis, for not demonstrated. This knowledge gap was recently heightened by the discovery of widespread motion, implying breakdown grains to sub-sand sizes. To address question we investigated source(s) in Aeolis Dorsa (AD), westernmost Medusae Fossae Formation, using comparisons potentially sourced from multiple regions, each connoting different genesis. Our methods included comparison (1) AD mineralogies with those possible source features, (2) mapped deposits inferred emplacement directions modeled deposit locations transport pathways. The results point time-transgressive unit, interpreted as pyroclastic, dark sand. High-resolution images this unit reveal outcrops weathering out lithified bedrock. Given extent pyroclastic Mars, genesis mechanism is likely today operated Whereas work identified olivine-rich sand, range original lithologies would account mineralogic variability dune fields Mars. These findings can be tested through analyses other data NASA Curiosity rover nearby Gale crater.