Mössbauer mineralogy of rock, soil, and dust at Gusev crater, Mars: Spirit's journey through weakly altered olivine basalt on the plains and pervasively altered basalt in the Columbia Hills

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Read Full Article (file size: 14436315 bytes) Cited by JOURNAL OF GEOPHYSICAL RESEARCH, VOL. 111, E02S13, doi:10.1029/2005JE002584, 2006 Mössbauer mineralogy of rock, soil, and dust at Gusev crater, Mars: Spirit's journey through weakly altered olivine basalt on the plains and pervasively altered basalt in the Columbia Hills R. V. Morris NASA Johnson Space Center, Houston, Texas, USA G. Klingelhöfer Institut für Anorganische und Analytische Chemie, Johannes Gutenberg-Universität, Mainz, Germany C. Schröder Institut für Anorganische und Analytische Chemie, Johannes Gutenberg-Universität, Mainz, Germany D. S. Rodionov Institut für Anorganische und Analytische Chemie, Johannes Gutenberg-Universität, Mainz, Germany Space Research Institute IKI, Moscow, Russia A. Yen Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California, USA D. W. Ming NASA Johnson Space Center, Houston, Texas, USA P. A. de Souza Jr. Institut für Anorganische und Analytische Chemie, Johannes Gutenberg-Universität, Mainz, Germany CVRD Group, Vitoria, Brazil I. Fleischer Institut für Anorganische und Analytische Chemie, Johannes Gutenberg-Universität, Mainz, Germany T. Wdowiak Department of Physics, University of Alabama at Birmingham, Birmingham, Alabama, USA R. Gellert Department of Physics, University of Guelph, Guelph, Ontario, Canada B. Bernhardt Institut für Anorganische und Analytische Chemie, Johannes Gutenberg-Universität, Mainz, Germany E. N. Evlanov Space Research Institute IKI, Moscow, Russia B. Zubkov Space Research Institute IKI, Moscow, Russia J. Foh Institut für Anorganische und Analytische Chemie, Johannes Gutenberg-Universität, Mainz, Germany Darmstadt University of Technology, Darmstadt, Germany U. Bonnes Darmstadt University of Technology, Darmstadt, Germany E. Kankeleit Darmstadt University of Technology, Darmstadt, Germany P. Gütlich Institut für Anorganische und Analytische Chemie, Johannes Gutenberg-Universität, Mainz, Germany F. Renz Institut für Anorganische und Analytische Chemie, Johannes Gutenberg-Universität, Mainz, Germany S. W. Squyres Center for Radiophysics and Space Research, Cornell University, Ithaca, New York, USA R. E. Arvidson Department of Earth and Planetary Sciences, Washington University, St. Louis, Missouri, USA Abstract The Mössbauer spectrometer on Spirit measured the oxidation state of Fe, identified Fe-bearing phases, and measured relative abundances of Fe among those phases for surface materials on the plains and in the Columbia Hills of Gusev crater. Eight Fe-bearing phases were identified: olivine, pyroxene, ilmenite, magnetite, nanophase ferric oxide (npOx), hematite, goethite, and a Fe³⁺-sulfate. Adirondack basaltic rocks on the plains are nearly unaltered (Fe³⁺/Fe_T < 0.2) with Fe from olivine, pyroxene (Ol > Px), and minor npOx and magnetite. Columbia Hills basaltic rocks are nearly unaltered (Peace and Backstay), moderately altered (WoolyPatch, Wishstone, and Keystone), and pervasively altered (e.g., Clovis, Uchben, Watchtower, Keel, and Paros with Fe³⁺/Fe_T ∼ 0.6–0.9). Fe from pyroxene is greater than Fe from olivine (Ol sometimes absent), and Fe²⁺ from Ol + Px is 40–49% and 9–24% for moderately and pervasively altered materials, respectively. Ilmenite (Fe from Ilm ∼3–6%) is present in Backstay, Wishstone, Keystone, and related rocks along with magnetite (Fe from Mt ∼10–15%). Remaining Fe is present as npOx, hematite, and goethite in variable proportions. Clovis has the highest goethite content (Fe from Gt = 40%). Goethite (α-FeOOH) is mineralogical evidence for aqueous processes because it has structural hydroxide and is formed under aqueous conditions. Relatively unaltered basaltic soils (Fe³⁺/Fe_T ∼ 0.3) occur throughout Gusev crater (∼60–80% Fe from Ol + Px, ∼10–30% from npOx, and ∼10% from Mt). PasoRobles soil in the Columbia Hills has a unique occurrence of high concentrations of Fe³⁺-sulfate (∼65% of Fe). Magnetite is identified as a strongly magnetic phase in Martian soil and dust. Received 1 September 2005; accepted 9 December 2005; published 22 February 2006. Keywords: Mars; Mars Exploration Rovers; Mössbauer spectroscopy; weathering. Index Terms: 5470 Planetary Sciences: Solid Surface Planets: Surface materials and properties; 5415 Planetary Sciences: Solid Surface Planets: Erosion and weathering; 5494 Planetary Sciences: Solid Surface Planets: Instruments and techniques; 6225 Planetary Sciences: Solar System Objects: Mars; 3929 Mineral Physics: NMR, Mossbauer spectroscopy, and other magnetic techniques. Read Full Article (file size: 14436315 bytes) Cited by Citation: Morris, R. V., et al. (2006), Mössbauer mineralogy of rock, soil, and dust at Gusev crater, Mars: Spirit's journey through weakly altered olivine basalt on the plains and pervasively altered basalt in the Columbia Hills, J. Geophys. Res., 111, E02S13, doi:10.1029/2005JE002584. Copyright 2006 by the American Geophysical Union.

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