Gypsum, Opal, and Fluvial Channels Within a Trough of Noctis
Planetary and Space Science 87 (2013) 130–145 Contents lists available at ScienceDirect Planetary and Space Science journal homepage: www.elsevier.com/locate/pss Gypsum, opal, and fluvial channels within a trough of Noctis Labyrinthus, Mars: Implications for aqueous activity during the Late Hesperian to Amazonian Catherine M. Weitz a,n, Janice L. Bishop b, John A. Grant c a Planetary Science Institute, 1700 E. Fort Lowell, Suite 106, Tucson, AZ 85719, United States b SETI Institute, 189 Bernardo Ave., Mountain View, CA 94043, United States c Center for Earth and Planetary Studies, National Air and Space Museum, Smithsonian Institution, 6th at Independence Ave. SW, Washington, DC 20560, United States article info abstract Article history: We investigate in detail the morphology, mineralogy, and stratigraphy of light-toned deposits within one Received 27 March 2013 trough of Noctis Labyrinthus, centered at À6.81N, 261.11E. CRISM spectra taken from light-toned layered Received in revised form deposits in the northern portion of the trough exhibit absorptions around 1.41, 1.92 and 2.21 μm, 3 July 2013 consistent with mixtures of opal and Al-clays that are exposed beneath younger lava flows and between Accepted 8 August 2013 high-standing mesas of chaotic terrain. In the southern portion of the trough, opal occurs as a patchy Available online 22 August 2013 surficial deposit along the southwestern lower wall. Gypsum appears to be present in the southern Keywords: portion of the trough where spectra show triplet absorptions at 1.44, 1.48, and 1.54 μm, and additional Mars absorptions at 1.20, 1.74, 1.95, 2.22, 2.27, and 2.49 μm.
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