INVESTIGATION OF HYDROTHERMAL CLAYS AND SULFATES IN TYRRHENA TERRA MARTIAN CRATERS (Invited Presentation)

We assessed the rare occurrences of Noachian-aged crustal sulfates and evaluated the implications of their presence in that region’s early Martian environments. We analyzed and mapped the mineral distribution of three craters in Tyrrhena Terra, which formed in early to middle Noachian highland crustal units, using visible-near infrared spectral and high-resolution morphologic data from MRO’s CRISM, CTX, and HiRISE instruments. The most common minerals detected in all three craters were polyhydrated sulfates, Mg/Fe-smectite, chlorite, and high- and low-calcium pyroxene (HCP and LCP, respectively), with distributions varying from widespread to local. Analcime, bassanite, and prehnite have also been detected, although not consistently between each crater. Also identified were small exposures of talc, gypsum, and Fe/Mg/Ca-carbonate. From this research, we concluded that the polyhydrated sulfates located in all three craters are consistent with formation prior to impact, within the Noachian crustal materials. Possible emplacement mechanisms include both subsurface hydrothermal or non-hydrothermal processes, as evaporates, precipitates, or from the dissolution and oxidation of precursor sulfides. Further work will focus on the geochemical interactions necessary to form and preserve these hydrated sulfates as well as understanding the potential hydrogeologic and climatic implications for the Noachian time period.