Geomorphology and Spectral Map of a region of Iani Chaos on Mars

MARIA ROJAS; MARA MANTEGAZZA; MAURO GABRIEL SPAGNUOLO; HERNÁN PABLO BARCELONA

Encuentro; 55TH ANNUAL MEETING OF THE DIVISION FOR PLANETARY SCIENCES JOINT WITH EPSC; 2023

Geomorphology and Spectral Map of a region of Iani Chaos on MarsMaria Rojas1, Mara Mantegazza1, Mauro Spagnuolo1, Hernán Barcelona1 1IDEAN UBA-CONICET, Autonomous City of Buenos Aires, ArgentinaChaotic terrains on Mars are partially enclosed basins surrounded by extensional fractured and eroded highlands, whose origin is complex and has been regarded as a result of different processes that may have resulted in massive outflows of groundwater which lead to a subsequent collapse of the surface. In this work, we focused the analysis on a northern region of Iani Chaos, characterized by chaotic morphologies such as highlands, knobby terrain, Light Toned Layered Deposits (LTLD), as well as aeolian deposits.The primary objective of this research is to analyze the geomorphology and mineral spectral signs of the region, with a particular focus on identifying hydrated minerals because these could have formed by the interaction between groundwater in a low temperature geothermal system. To this end, we produced a detailed map of the region, to investigate the hypothesis of a potential active geothermal system in the past.A survey of the northern region of Iani Chaos was made based on CTX-Mosaic images, also HiRISE images and CRISM hyperspectral cubes that have been used to build a database for the analysis and definition of the units. Then, the map was produced using open-source software QGIS.The resulting map shows various geomorphological features in the study area, which can be attributed to the mass wasting processes. These features include Highland mounds, Highland rough-surface, Dissected central mound. Overlying these units is a sedimentary cover, consisting of smooth and loose materials, classified as Mantling, Aeolian Bedforms and Slope Material. The morphology indicates that the area is an old impact basin.Furthermore, from the analysis of spectral data we identified specific mineral composition within the study region. Fe-Mg hydrated phyllosilicates, Fe-Mg smectites, and Al-Si hydrated phyllosilicates have been characterized as the predominant spectral units. In addition, LTLD have also been recognized as hydrated sulfates.According to this, the spectral units exhibit a correlation with geomorphological units as follows: Mono- and polyhydrated sulfates are associated with LTLD, a layered unit that is exposed on several hillslopes. On the other hand, Fe-Mg smectites have been observed in an outcrop located in a low-topographic region. Additionally, Al-Si hydrated phyllosilicates, such as kaolinite and smectite, have been identified on the rough surface on the highland unit, these sediments exhibit evidence of wind reworking, and also a small patch of Al-Si hydrated phyllosilicates has been detected adjacent to the central dissected mound, situated in a topographically low zone.