HR: 1340h
AN: P13D-1558    [Abstracts]
TI: Phyllosilicate identification in Mawrth Vallis: an analysis of CRISM multispectral data and targeted images FRT4ECA and HRS307A
AU: * McKeown, N K
EM: nmckeown@pmc.ucsc.edu
AF: University of California, Santa Cruz, Earth and Planetary Sciences 1156 High St., Santa Cruz, CA 95064, United States
AU: Bishop, J L
AF: SETI Institute/NASA-ARC, 515 N. Whisman Rd., Mountain View, CA 94043, United States
AU: Noe Dobrea, E
AF: Jet Propulsion Laboratory, 4800 Oak Grove Dr., Pasadena, CA 91109, United States
AU: Ehlmann, B L
AF: Brown University, Department of Geological Sciences, Providence, RI 02912, United States
AU: Mustard, J F
AF: Brown University, Department of Geological Sciences, Providence, RI 02912, United States
AU: Murchie, S L
AF: The Johns Hopkins University Applied Physics Laboratory, 11100 Johns Hopkins Rd, Laurel, MD 20723, United States
AU: Bibring, J
AF: Institut d'Astrophysique Spatiale, Batiment 121 Universite Paris Sud, Orsay, 91405, France
AU: Poulet, F
AF: Institut d'Astrophysique Spatiale, Batiment 121 Universite Paris Sud, Orsay, 91405, France
AU: Silver, E
AF: University of California, Santa Cruz, Earth and Planetary Sciences 1156 High St., Santa Cruz, CA 95064, United States
AU: Malaret, E
AF: Applied Coherent Technology, Inc., 112 Elden St., Herndon, VA 20170, United States
AU: Hash, C
AF: Applied Coherent Technology, Inc., 112 Elden St., Herndon, VA 20170, United States
AU: CRISM team, a
AB: Large exposures of Al- and Fe/Mg-phyllosilicates have been identified in the Mawrth Vallis region using data from OMEGA (Poulet, F., Bibring, J.- P., Mustard, J. F., Gendrin, A., Mangold, N., Langevin, Y., Arvidson, R. E., Gondet, B. & Gomez, C., 2005, Nature, 438, 632-627; Noe Dobrea and Michalski, 2006, AGU Fall Meeting 2006, #P23D-009; Loizeau et al 2007, JGR, 112 (E8), 10.1029/2006JE002877) and CRISM. Regional mapping with CRISM multispectral data shows an excellent correlation with OMEGA results. The higher-resolution CRISM multispectral mapping data improve upon the OMEGA detections, finding additional, smaller deposits. We have identified several Al- and Fe/Mg-phyllosilicate minerals in three 5x5 degree multispectral map tiles projected at 256 pixels per degree and high-resolution hyperspectral images HRS307A and FRT4ECA. HRS307A lies within the southern part of the main channel and contains units exposed by channel creation, allowing us to study its depositional history. FRT4ECA is northeast of HRS307A, just south of the northern part of the main channel and contains knob-type features not seen in abundance in other Mawrth images. In FRT4ECA, Fe/Mg-phyllosilicates such as nontronite have been identified using the characteristic absorptions at 2.41um, 2.28um, 1.91um, and 1.42um and Al-phyllosilicates such as montmorillonite by the characteristic absorptions at 2.21 um, 1.91 um, and 1.41um. These two minerals occur in two distinct layers and are consistent with mineral species identified in other regions of Mawrth, implying wide-spread deposition in an aqueous environment rather than local hydrothermal alteration. Smaller exposures of other phyllosilicates such as kaolinite and ferrosaponite have also been observed indicating a variety of aqueous processes in this region.
DE: 5464 Remote sensing
DE: 5470 Surface materials and properties
DE: 6225 Mars
SC: Planetary Sciences [P]
MN: 2007 Fall Meeting