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Mawrth Vallis – Considerations for Habitability and Biosignature Preservation to be discussed in more detail July 28 telecon. Evaluation of support for biosignature formation, concentration, and preservation (FCP) for impact-related rocks.
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Mawrth Vallis – Considerations for Habitability and Biosignature Preservationto be discussed in more detail July 28 telecon Mawrth Vallis LSWG Hab/BiosigPres, Jen Eigenbrode/ NASA GSFC
Evaluation of support for biosignature formation, concentration, and preservation (FCP) for impact-related rocks • Impacts provide heat that can linger for 1000’s to 10,000’s years (more?) • Water, chemical and thermal energy flux Support for Biosignature FCP Post-impact impact-generated hydrothermal system (surface and subsurface) high Do we have this at Mawrth in rover range? impact-generated crater lake high Pre-Impact Rocks IMPACT impact-related fluvial environments low impact-independent sediments accumulated in catchment Dependent on depositional environment ? impact-independent diagenetic conditions (e.g. pedogenesis) low Was this a significant process at Mawrth in the rover area? Mawrth Vallis LSWG SOWG Hab/BiosigPres, J. Eigenbrode/ NASA GSFC
Evaluation of support for biosignature formation, concentration, and preservation (FCP) for impact-related rocks Impact craters provide access to bedrock Post-impact Sedimentary record that supports biosignature FCP • Biosignatures in sedimentary rock that are excavated from or proximal to impact craters are susceptible to alteration/destruction by: • impact erosion, subsequent oxidation and weathering • shock metamorphism* • hydrothermal alteration* • redistribution* • overprinting by later life* • Context and framework complicated or lost. • Details saved for future telecon. With respect to Mawrth… Searching for habitability features and biosignatures from the time of rock deposition is an option for a Mawrth MSL investigation, but risky given so many uncertainties. optimism IMPACT Pre-Impact Rocks Mafic rock/ lava (biosignature FCP unlikely) • No pre-impact biosignatures to preserve Subsurface viable life Topic of future discussion Mawrth Vallis LSWG Hab/BiosigPres, J. Eigenbrode/NASA GSFC