Understanding Mars' LARLE Craters

Origin of the outer layer of Martian low-aspect ratio layered ejecta craters

Authors:

Boyce et al

Abstract:

Low-aspect ratio layered ejecta (LARLE) craters are one of the most enigmatic types of Martian layered ejecta craters. We propose that the extensive outer layer of these craters is produced through the same base surge mechanism as that which produced the base surge deposits generated by near-surface, buried nuclear and high-explosion detonations. However, the LARLE layers have higher aspect ratios compared with base surge deposits from explosion craters, a result of differences in thicknesses of these layers. This is probably caused by the addition of large amounts of small particles of dust and ice derived from climate-related mantles of snow, ice and dust in the areas where LARLE craters form. These deposits are likely to be quickly stabilized (order of a few days to a few years) from eolian erosion by formation of duricrust produced by diffusion of water vapor out of the deposits.