Paper No. 5
Presentation Time: 9:10 AM
EOLIAN FEATURES AT THE BASE OF MT. SHARP, AND RELATION TO WINDS IN GALE CRATER, MARS
RUBIN, David M., Pacific Coastal and Marine Science Center, US Geological Survey, 400 Natural Bridges Drive, Santa Cruz, CA 95060, KOCUREK, Gary, Geological Sciences, Jackson School of Geosciences, The University of Texas at Austin, 1 University Station C9000, Austin, TX 78712, BRIDGES, Nathan, Jet Propulsion Laboratory, 4800 Oak Grove Dr, Pasadena, CA 91109-8001, GROTZINGER, John P., Earth and Planetary Sciences, Caltech, 1200 E. California Ave, Pasadena, CA 91125, GUPTA, Sanjeev, Earth Science and Engineering, Imperial College London, South Kensington Campus, London, SW7 2AZ, United Kingdom, LEWIS, Kevin, Department of Geosciences, Princeton, Princeton, NJ 08544, NEWMAN, Claire E., Ashima Research, 600 S. Lake Avenue, Suite 104, Pasadena, CA 91106, RENNO, Nilton O., Atmospheric, Oceanic and Space Sciences, University of Michigan, Ann Arbor, MI 48109-2143, SULLIVAN, R., Department of Astronomy, Cornell University, Ithaca, NY 14853 and TEAM, MSL Science, Jet Propulsion Laboratory, Pasadena, CA 91101, drubin@usgs.gov
Eolian processes are important to the geomorphologic and sedimentary history of Gale Crater, Mars, from the sediment budget of the crater to possibly the growth of the central mound. Gale Crater contains active dunes and ripples, lithified dunes, and sets of cross-beds deposited by migrating dunes. Some dunes are actively migrating or support active superimposed ripples. These dunes are dark and occur in a belt that trends northeast/southwest directly in the path between the Mars Science Laboratory landing site and Mt. Sharp. The active dune field includes interacting isolated barchans in the north and west portions of the dune field and linear dunes in the southern part.
Dunes that are light-toned have been inferred to be dust-covered and therefore inactive. They are smaller than the dark active dunes, and commonly occur within the troughs of the large dark dunes. They often have a polygonal or “ladderback” planform geometry.
The base of Mt. Sharp also includes strata that have been lithified, but contain bedding surfaces that resemble dunes in planform; these features have been previously described as “washboard” structures. Close examination shows that some of these structures are not dune forms, but rather are relatively planar sections excavated through sets of cross-beds.
Wind conditions in Gale Crater have been inferred from dune geometry and from observed migration of ripples superimposed on the dunes, and winds have been predicted using mesocale wind models. One of the goals of MSL is to make direct measurements of winds and sand transport that can be used to test model predictions. Here we report on the integration of these multiple approaches to understanding and quantifying eolian processes and crater morphodynamics.
