Geomorphological and Photogeological Units Map of Cilaos Crater: interpretation of landforms and surface processes in Eastern Promethei Terra, Mars

Abstract

A detailed geomorphological mapping is essential to describe the spatial distribution, morphometry, and genesis of Martian landforms, and to better understand the processes that have shaped and continue to influence the planet’s surface morphology. However, high-resolution thematic cartography of Mars is still largely lacking despite its critical importance for the interpretation of surface processes and the planning of future exploration missions. This study focuses on Cilaos Crater (35.72° S, 129.45° E, eastern Promethei Terra), a site of particular interest due to the presence of the young Gasa Crater (7 km in diameter) within its boundaries. We present a detailed geomorphological map of the Cilaos region, created through remote sensing analysis using high-resolution imagery from the Mars Reconnaissance Orbiter and topographic data from the Mars Orbiter Laser Altimeter (MOLA), processed within a GIS framework. Photointerpretation allowed us to produce a 1:25,000 scale geomorphological map, differentiating photogeological units as well as erosional and depositional landforms shaped by various morphogenetic processes. Our analysis highlights the significant impact of Gasa Crater's formation on the surrounding landscape. The interaction between the degrading latitude-dependent mantle (LDM) and Gasa’s impact ejecta has played a crucial role in shaping flow-like structures and modifying pre existing terrain. This underscores the importance of the interplay of impact events and periglacial environment in shaping the Martian surface during the late Amazonian. Furthermore, by reconstructing the relative chronology of landforms, deposits, and photogeological units, we link the relatively young age of Gasa Crater to the broader landscape evolution of the Cilaos region. This study provides new insights into the ongoing geomorphic processes that continue to shape Mars' mid-latitudes.