Evidence for a Possible Supervolcano on Mars at Siloe Patera

Abstract

Highlands on Mars interpreted as impact craters may instead be supervolcanoes within an ancient volcanic province in Arabia Terra, Mars. These volcanoes are characterized by lower than normal topographic relief, collapse features, layered deposits, as well as effusive volcanism and explosive eruptions. Seven features are to be considered part of the new volcanic field, which includes Siloe Patera. Although an alternative hypothesis for Siloe Patera’s origin is nested impact craters, evidence points more towards multiple caldera collapses or a combination of impact and caldera collapse events. Regions of interest in and around Siloe Patera include: (1) possible volcanic-doming along the bench; (2) possible ring faulting on the eastern portion of the bench; (3) a spire located on the floor of Siloe Patera; and (4) flow features around Siloe Patera. Data from various Martian orbiters was used to analyze Siloe Patera, Ascraues Mons, a nested crater and three random craters roughly the size of Siloe Patera. Data collection included gathering raw Mars Orbital Laser Altimeter (MOLA) tracks over Siloe Patera, Thermal Emission Imaging System (THEMIS) Night Infrared, Context Camera (CTX), and Mars Orbiter Camera (MOC) images. Utilizing data currently available, characteristics of Siloe Patera resemble that of a volcano more than that of an impact crater based on topographic profiles, depth diameter ratios, slope angles, and comparison of regions of interest.