A review of Martian impact crater ejecta structures and their implications for target properties

Most fresh Martian impact craters are surrounded by layered (fl uidized) ejecta which were emplaced as flow deposits. Observational data, laboratory experiments, and numerical modeling strongly suggest that particle size, particle density, atmospheric density and pressure, and the presence of subsurface volatiles all contribute to the features observed in these craters and their ejecta blankets. In this co tribution, we review the evidence that both subsurface volatiles and the thin Martian atmosphere contribute to the morphologic, morphometric, and thermophysical characteristics of Martian impact craters and their ejecta deposits. © 2005 Geological Society of America.