Formation and Diagenesis of Sedimentary Rocks in Gale Crater, Mars
The Mars Science Laboratory rover Curiosity has explored over 200 m of exposed crater-fill stratigraphy dominated by fluvio-deltaic sandstones and lacustrine mudstones. During this traverse, Curiosity has acquired over 400 bulk chemistry measurements of in-situ sedimentary rock surfaces using an Alpha-Particle X-ray Spectrometer (APXS). Each of these compositions represents a mixture of volcaniclastic detrital grains sorted by transport processes and cemented by diagenetic fluids, but we can begin to separate these distinct influences and understand source-to-sink processes on Mars when we place the observations within their stratigraphic context. I will show, using geochemical and mineralogical models, what we have learned about the volcanic source rocks, the importance of sediment transport processes, and the chemistry of authigenic and diagenetic fluids in each of the three major sedimentary units in Gale crater.