Surficial Investigations of Hargraves Crater and Siloe Patera, Mars

Abstract

This study investigates Hargraves crater and Siloe Patera of Mars. Individual barchan and barchanoids dunes in Hargraves were almost accurately identified using a semi-automated object-based image analysis technique. The dunes have an effective grain-size of ~230 μm (fine sand) and are composed of a mixture of feldspar, olivine, pyroxene, and relatively lower bulk-silica phase. Having a debated geologic history of Siloe Patera, this study resolved the possible origin hypothesis. The feature has experienced multiple geologic processes; initially formed as an impact crater, followed by subsequent modification by fluvial activities and/or periglacial reworking and, then, followed by a major collapse event due to primarily cryospheric subsurface ice-removal resulting in melting of accumulated subsurface snow and ice deposits that formed boomerang lake and fresh shallow valley system in conjunction with possible effusive lava flow and volcanic heating. Later, the depression underwent glacial reworking and recent aeolian modification.