BASALT A: Basaltic Terrains in Idaho and Hawaii as Planetary Analogues for Mars Geology and Astrobiology.

Field research target regions within two basaltic geologic provinces are described as Earth analogues to Mars. Regions within the eastern Snake River Plain of Idaho and the Big Island of Hawaii, the United States, provinces that represent analogues of present-day and early Mars, respectively, were evaluated on the basis of geologic settings, rock lithology and geochemistry, rock alteration, and climate. Each of these factors provides rationale for the selection of specific targets for field research in five analog target regions: (1) Big Craters and (2) Highway lava flows at Craters of the Moon National Monument and Preserve, Idaho, and (3) Mauna Ulu low shield, (4) Klauea Iki lava lake, and (5) Klauea caldera in the Klauea Volcano summit region and the East Rift Zone of Hawaii. Our evaluation of compositional and textural attributes, as well as the effects of syn- and posteruptive rock alteration, shows that basaltic terrains in Idaho and Hawaii provide a way to characterize the geology and major geologic substrates that host biological activity of relevance to Mars exploration. This work provides the foundation to better understand the scientific questions related to the habitability of basaltic terrains, the rationale behind selecting analog field targets, and their applicability as analogues to Mars.