Reassessing landslide deformation in Ganges Chasma, Mars

High-resolution images of landslide aprons in Ganges Chasma show extensive scarps, rock chutes, and talus accumulations on the canyon rim. Below these exists a topographic bench formed of multiple terraces, ridges and scarps. The terrace slopes are talus covered similar to the canyon rim. Small volume lobes and sheets originate from talus accumulations and extend downslope. While previously determined to be the result of large volume catastrophic landslides, the characteristics and dimensions of the terraces forming the topographic bench can be explained by deep-seated gravitational creep of the ancient rock mass. Gravity driven movements over millions of years can also account for the morphology and dimensions of talus lobes thus offering an alternative to catastrophic long-runout landslide mechanisms. The movement of lobes is suggested to be analogous to terrestrial periglacial rock glaciers.