Cycles of change: Long and short term aeolian evolution at the Olympus Maculae, Mars

The low-dust Olympus Maculae are a unique geologic window to the local volcanic and aeolian stratigraphy on Mars. The Maculae display dust-cover changes associated with the 2018 global dust storm and dust devils confined to the dark maculae. Regional yardangs and sand patches indicate erosion and deposition and thus strong wind, yet we have not observed meter-scale ripple movement within the dark sand deposits nor decameter-scale ripple movement more regionally. On longer timescales, yardangs along a continuum of morphologies point to cycles of abrasion, infilling, lithification , and re-abrasion. Together, the dust changes and yardang evolution bracket the timescales for landscape evolution in and around the Maculae. • Low-dust “windows” (maculae) into near-subsurface stratigraphy on the Olympus Mons aureole deposit reveal cross bedding. • Prevalent U-shaped yardangs appear in various stages of formation and degradation. • These maculae may reveal underlying processes into the creation and destruction of yardangs in this friable lithology.