Sediments within the icy North Polar Deposits of Mars record recent
Impacts and Volcanism
Abstract
The 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.