Bedform interaction strata exposed in transverse aeolian ridges on Mars

Abstract:

Interactions between individual bedforms drive changes in bedform patterns. When dunes interact, the cross strata left behind necessarily reflect the interaction event and the linking or merging of the bedforms. Interaction bounding surfaces have been identified in ancient aeolian strata and young subsurface strata, but no modern examples have been identified on Earth. Separately, aeolian bedforms on Mars include enigmatic straight-crested bedforms termed “transverse aeolian ridges”. These bedforms are abundant on Mars, but largely immobile over decadal timescales, leading to debate about whether they grew in place or migrated to their observed position. In this work, interaction bounding surfaces exposed on the stoss sides of martian bedforms show the first in-situ examples of interaction surfaces in modern bedforms, and confirm that transverse aeolian ridges migrate and interact like typical transverse dunes.