Title: "Redox stratification of an ancient lake in Gale Crater, Mars"
Abstract: In 2012, NASA’s Curiosity rover landed on Mars to assess its potential as a habitat for past life and investigate the paleoclimate record preserved by sedimentary rocks inside the ~150-kilometer-diameter Gale impact crater. Geological reconstructions from Curiosity rover data have revealed an ancient, habitable lake environment fed by rivers draining into the crater. I will present a synthesis of geochemical and mineralogical data from lake-bed mudstones collected during the first 1300 martian solar days of rover operations in Gale. This data provides evidence for lake redox stratification, established by depth-dependent variations in atmospheric oxidant and dissolved-solute concentrations. Paleoclimate proxy data indicate that a transition from colder to warmer climate conditions is preserved in the stratigraphy. Finally, a late phase of geochemical modification by saline fluids is recognized. Results from Gale crater will be compared to Martian sedimentary deposits investigated by the Mars Exploration Rover Opportunity to provide broad constraints on the evolution of Martian climate conditions during the late Noachian to early Hesperian periods (ca. 3.1-3.8 Ga). [Background Reading]