GSA Connects 2021 in Portland, Oregon

Paper No. 146-7
Presentation Time: 9:55 AM


ARVIDSON, Raymond, Earth and Planetary Sciences, Washington University IN St. Louis, 1 Brookings Drive, St. Louis, MO 63130

The joint analysis of Mars Reconnaissance Orbiter Compact Imaging Spectrometer for Mars (CRISM) hyperspectral (0.362 to 3.92 µm) imaging data with both Opportunity and Curiosity Rover observations has proven to be value added in many ways. For example, CRISM-based spectral detections of ferric smectites on the rim of the Noachian-age Endeavour Crater led the Opportunity Science Team to drive the rover to the detected locations, Cape York and Marathon Valley, for detailed measurements. The result was the discovery of uplifted, slightly altered crust lying beneath Endeavour ejecta deposits. For Curiosity, CRISM spectra showed the presence of crystalline hematite on the Vera Rubin Ridge, located on the flanks of Aeolis Mons (informally, Mount Sharp). The detection locations were used to command Curiosity to key spots for detailed observations. The combined data sets showed that the hematite occurrences cross stratigraphic boundaries within the Murray formation lacustrine deposits and are indicative of post-deposition, groundwater-based alteration. CRISM data also indicated the presence of ferric smectites in the nearby Glen Torridon and Curiosity observations correlate well with the detections. On the other hand, Curiosity data showed the presence of smectites all the way back to measurements in Yellowknife Bay, where there were no CRISM-based detections. The lesson-learned is that the presence of a thin (micrometers) dust cover over outcrops in Yellowknife Bay was enough to obscure the CRISM-based VISIR spectral detections. Curiosity is continuing its ascent of Mount Sharp and on its way to examine in detail the CRISM-based detections of sulfate-bearing strata that are indicative of a major climatic shift from a fluvial-deltaic-lacustrine to evaporate-dominated sedimentary environments. The expectation is that synergistic analyses of the orbital and rover-based observations will provide detailed insights into the nature of this key shift in environmental conditions on Mars.