Geologic Map and Interpreted Formation of Chaos Terrain in Galilaei crater, Mars

Abstract:

This research focuses on the interpretation of chaos terrain in an unusual paleo-lake formed in Galilaei crater, Mars. Galilaei crater is located in the Margaritifer Terra region of Mars at 5.7°N, 333.0°E, approximately 137 km in diameter. A geologic map was constructed using CTX and HiRISE images to identify the location of chaos terrain, inflow, and outflow channels within Galilaei crater. Chaos terrains are found near the crater rim, concentrated on the southwest corner, near the head of an outflow channel, Tana Vallis. Similar layers exposed within the chaos terrain blocks and crater walls were observed in HiRISE images, suggesting large scale sliding of blocks from the crater rim may have influenced the formation of concentrated chaos terrains within the crater interior. This sliding ranged from 1-70km from the crater wall in different areas within Galilei crater and must have been influenced by the local hydrology, including, potentially, melting or movement of near-surface ice. The geologic mapping produced in this work suggests a dynamic relationship between the hydrological processes and chaotic terrain formation which can be used to further understand the geological history of Margaritifer Terra.