Postdating of flow in Athabasca Valles by faulting of the Cerberus Fossae, Elysium Planitia, Mars

Abstract

Mars Orbiter Laser Altimeter (MOLA) topographic data, High Resolution Imaging Science Experiment (HiRISE), Thermal Emission Imaging System (THEMIS), and Mars Orbiter Camera (MOC) images have been used to study the timing of the formation of Athabasca Valles relative to faulting of the southern Cerberus Fossae (SCF). The topography of Athabasca Valles, derived from MOLA elevation data, appears as two troughs on the north and south footwalls of SCF. The same troughs can be identified on the floor of the fossae, indicating that Athabasca Valles predates the accumulation of ∼500 m of vertical fault offset. The topographic expression of Athabasca Valles is preserved on the graben floor because infill by sediment and lava, since formation of the valles and fossae, amounts to less than a few tens of meters. We use this information to discuss the mode of formation of Athabasca Valles and Cerberus Fossae.