Paper No. 12
Presentation Time: 4:05 PM
EVOLUTION OF ARGYRE BASIN AND SURROUNDINGS AND ASTROBIOLOGICAL IMPLICATIONS
The Argyre impact created a giant catchment for water and rock materials since roughly 3.93 Ga based on detailed stratigraphy and crater statistics unfolded through a NASA PG&G mapping project. A giant lake formed in the aftermath of the event (likely related to impact-generated meltwater from an ice sheet and associated rainfall and migration of subsurface and surface water into the basin), feeding the far-reaching Uzboi Vallis system, with a volume nearing that of the Mediterranean Sea; other lakes filled the impact-derived local basins as well. The lakes would soon freeze and the once lacustrine environment would transition into glacial and periglacial environments. Through time, liquid water/water-ice would wane, though not totally being depleted, as there would be subsequent Tharsis-driven, transient hydrological cycling (including enhanced geological and climatic activities). Water enrichment in the Argyre basin (including valleys and local basins among the rim materials) continues until present-day. Examples of geologically-recent and/or present-day activity includes the formation of small-sized polygonal-patterned ground, gullies and possible open-system pingos, flow-like features of the valley-fill materials, which includes glacier-like features, and activity along graben-like features.
Mars is the prime target to search for life beyond Earth, as it once had Habitable-Trinity conditions (i.e., interaction among landmass, ocean, and atmosphere; see Dohm and Maruyama, this conference) prior to the Argyre impact event. The long-term water enrichment, heat generation from the Argyre impact, basement structures which piped water into the basin from far-reaching geologic provinces, potential nutrient-enriched primordial crustal materials, extant ice, potential near-surface groundwater in places, and potential venting of magma and volatiles collectively point to the Argyre basin region as a prime candidate for future exploration of possible life.