Alberto G. Fairén, James M. Dohm, J. Alexis P. Rodríguez, Esther R. Uceda, Jeffrey Kargel, Richard Soare, H. James Cleaves, Dorothy Oehler, Dirk Schulze-Makuch, Elhoucine Essefi, Maria E. Banks, Goro Komatsu, Wolfgang Fink, Stuart Robbins, Jianguo Yan, Hideaki Miyamoto, Shigenori Maruyama, Victor R. Baker. 2016. The Argyre Region as a Prime Target for in situ Astrobiological Exploration of Mars. Astrobiology 16, 2, 143-158, DOI: 10.1089/ast.2015.1396
At the time before similar to 3.5 Ga that life originated and began to spread on Earth, Mars was a wetter and more geologically dynamic planet than it is today. The Argyre basin, in the southern cratered highlands of Mars, formed from a giant impact at similar to 3.93 Ga, which generated an enormous basin approximately 1800 km in diameter. The early post-impact environment of the Argyre basin possibly contained many of the ingredients that are thought to be necessary for life: abundant and long-lived liquid water, biogenic elements, and energy sources, all of which would have supported a regional environment favorable for the origin and the persistence of life. We discuss the astrobiological significance of some landscape features and terrain types in the Argyre region that are promising and accessible sites for astrobiological exploration. These include (i) deposits related to the hydrothermal activity associated with the Argyre impact event, subsequent impacts, and those associated with the migration of heated water along Argyre-induced basement structures; (ii) constructs along the floor of the basin that could mark venting of volatiles, possibly related to the development of mud volcanoes; (iii) features interpreted as ice-cored mounds (open-system pingos), whose origin and development could be the result of deeply seated groundwater upwelling to the surface; (iv) sedimentary deposits related to the formation of glaciers along the basin’s margins, such as evidenced by the ridges interpreted to be eskers on the basin floor; (v) sedimentary deposits related to the formation of lakes in both the primary Argyre basin and other smaller impact-derived basins along the margin, including those in the highly degraded rim materials; and (vi) crater-wall gullies, whose morphology points to a structural origin and discharge of (wet) flows. Key Words: Mars-Surface processes and composition of Mars-Liquid water-Geological conditions for the development of life-Planetary habitability and biosignatures. Astrobiology 16, 143-158.