All large craters in the image show dark deposits either on their floors or along their walls (see annotated image). A closer look at Trouvelot Crater reveals that this dark material has accumulated into dunes formed by wind-driven (aeolian) processes – specifically, a type known as barchan dunes (see annotated image). Regions on Mars covered by dark material are known to be rich in mafic minerals such as pyroxene and olivine. These dark intra-crater deposits may have originated from a thick subsurface layer of volcanic sediments rich in mafic minerals. Large impacts, like those that formed the craters seen in the HRSC image, could have cut through this buried layer, exposing the dark material along the crater floors and walls. Once exposed, the material was redistributed by wind and gravity-driven transport down the crater walls, forming the dark sheets and dunes visible today. When zooming out from Trouvelot Crater, it becomes evident that most large craters in the surrounding area of Arabia Terra also reveal these dark deposits – indicating that they are not merely a local feature, but part of a more widespread phenomenon on Mars.