Sediments Within the Icy North Polar Deposits of Mars Record Recent Impacts and Volcanism

Abstract

AbstractThe North Polar Layered Deposits (NPLD) of Mars are ice‐rich sedimentary layers that formed under the influence of Mars' modern climate and thus record the recent climatic history of Mars, analogous to terrestrial ice sheets. The 2013–2023 Planetary Science Decadal Survey recommends a lander mission to sample the NPLD for climatic records; however, linking the geologic record to the climatic history will require quantitative dating of the NPLD. In this study we use orbital reflectance spectroscopy to show for the first time that dateable mafic lithics are present throughout the NPLD. We find significant glass as well as diverse crystalline minerals, which suggests that surface processes like impacts and volcanism were active during the late Amazonian and transported sediments from across the planet to the north pole. In situ investigation of the NPLD will thus provide critical quantitative constraints on both the recent geologic and climatic histories of Mars.