Experimental Aeolian Abrasion of Basalt Sands as an Analog for Producing Martian Dust

Abstract

Dust covers a significant portion of Mars' surface, with dust storms periodically engulfing the planet. Despite this, the origins of Martian dust are poorly understood, especially for ancient dust deposits. To address this deficit, we conducted experiments to replicate the mechanical abrasion of saltating sand grains in a Martian desert dune field under storm wind conditions, measured rates and particle‐size distributions of produced dust, and scaled results to determine potential planetary‐wide significance. Two basalt sand samples were collected to act as Martian dune sand analogs (from Hawaii and Iceland). Samples were processed to remove any pre‐existing dust‐sized sediment and then abraded inside a novel device designed to replicate the grain‐on‐grain collisions experienced by saltating sand in a desert aeolian system. These experiments demonstrate the significance of dust production by aeolian saltation of basalt sand at the planetary scale. Results show that basaltic sand from Iceland produced 4 times more dust and 2.5 times more fine sand than Hawaiian samples, suggesting that differences in composition, shape, and size of the sand grains influence the amount of dust produced. If our experiments are valid replications of natural dust production, then aeolian saltation over 1 million to 1 billion years on Mars could produce a geologically significant amount of dust capable of influencing the planetary climate. These results have implications for the deep time climate of Mars when the atmosphere was denser, and aeolian saltation was more frequent.