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Discovery of alunite in Cross crater, Terra Sirenum, Mars: Evidence for acidic, sulfurous waters

July 1, 2016

Cross crater is a 65 km impact crater, located in the Noachian highlands of the Terra Sirenum region of Mars (30°S, 158°W), which hosts aluminum phyllosilicate deposits first detected by the Observatoire pour la Minéralogie, L’Eau, les Glaces et l’Activitié (OMEGA) imaging spectrometer on Mars Express. Using high-resolution data from the Mars Reconnaissance Orbiter, we examine Cross crater’s basin-filling sedimentary deposits. Visible/shortwave infrared (VSWIR) spectra from the Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) show absorptions diagnostic of alunite. Combining spectral data with high-resolution images, we map a large (10 km × 5 km) alunite-bearing deposit in southwest Cross crater, widespread kaolin-bearing sediments with variable amounts of alunite that are layered in

Publication Year 2016
Title Discovery of alunite in Cross crater, Terra Sirenum, Mars: Evidence for acidic, sulfurous waters
DOI 10.2138/am-2016-5574
Authors Bethany L. Ehlmann, Gregg A. Swayze, Ralph E. Milliken, John F. Mustard, Roger N. Clark, Scott L. Murchie, George N. Breit, James J. Wray, Brigitte Gondet, Francois Poulet, John Carter, Wendy M. Calvin, William Benzel, Kimberly D. Seelos
Publication Type Article
Publication Subtype Journal Article
Series Title American Mineralogist
Index ID 70185026
Record Source USGS Publications Warehouse
USGS Organization Crustal Geophysics and Geochemistry Science Center
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