Morphology of the north-western wall of Eos Chaos, Valles Marineris: Evidence for glaciation during late Amazonian high obliquity

Abstract

Glacial landforms have been reported from various regions on Mars; most notably from the mid-to-high latitude regions. We studied Eos Chaos, located towards the eastern boundary of Valles Marineris, for the possible glacial processes occurring in the low-latitude areas on Mars. A thorough investigation of the morphology of the north-western wall of Eos Chaos was carried out using planetary datasets such as context camera (CTX) and High-resolution Imaging Science Experiment (HiRISE) images from NASA's Mars Reconnaissance Orbiter (MRO) mission and Mars Color Camera (MCC) images from ISRO's Mars Orbiter Mission-1 (MOM-1). We identified various geomorphological features that may have resulted from diverse geological processes. The glacial processes are manifested by the morphological features such as tongue-shaped lobate flows, alternative dark and light strata (~10-15 m thick), light-toned fragmented sediments, kettle lake-like structures, surface striations, sublimation hollows, and pit and knob structures. The flow features correspond to three stages of evolution: developing (~0.3 km length), intermediate size (1.5 km length), and mature (~15 km length). These three stages culminated in developing a model depicting the evolution of the glacial landforms of the region based on morphological features. We deduce that the glacial landforms of the region were formed during episodes of higher planetary spin axis obliquity during the late Amazonian.