Landslide chronology on mars: A window into the past of Valles Marineris and martian slopes

Martian landslide deposits provide valuable insights into the planet's geomorphological evolution. Their degree of preservation is such that they can be recognized after billions of years. Therefore, a study of Martian landslides may reveal clues as to the surface and environmental conditions at the moment of collapse. In particular, determining their age is of great importance for reconstructing the geomorphological and structural evolution of the Martian surface. We conducted a comprehensive age dating analysis of 32 clusters, encompassing 102 landslides and 38 non-landslide units across various Martian regions. Most of the landslides dated in this work are considered here for the first time, while for several others we present an updating of their age, allowing for a validation of previous dating, and a broader geomorphological interpretation. Important factors affecting age determination such as landslide type, secondary craters, and resurfacing processes have been examined in detail to improve data quality and provide more robust conclusions. While very low frequency of slope collapse is observed between 3.2 and 2.4 Ga after a period of higher instability as confirmed by fluvial and glacial features, the overall trend of increasing frequency with time remains dominant. This is consistent with previous studies, and is now supported by a significantly larger dataset which modifies existing age determinations. This suggests the presence of a large number of ancient undetected landslides, buried beneath more recent deposits. This research provides new insights into the timing and frequency of mass wasting events on Mars, contributing to a better understanding of the planet's geomorphological evolution.