Mineralogy at Gusev Crater from the Mössbauer spectrometer on the Spirit Rover.
Mössbauer spectra measured on Mars by the Spirit rover during the primary mission are characterized by two ferrous iron doublets (olivine and probably pyroxene) and a ferric iron doublet (tentatively associated to nanophase ferric iron oxide). Two sextets resulting from nonstoichiometric magnetite are also present, except for a coating on the rock Mazatzal, where a hematite-like sextet is present. Greater proportions of ferric-bearing phases are associated with undisturbed soils and rock surfaces as compared to fresh rock surfaces exposed by grinding. The ubiquitous presence of olivine in soil suggests that physical rather than chemical weathering processes currently dominate at Gusev crater.
NASA Johnson Space Center, Houston, TX, USA. richard.v.morris@nasa.gov
R V
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Morris
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Klingelhöfer
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Bernhardt
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Schröder
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Rodionov
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De Souza
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Yen
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Gellert
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Evlanov
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Foh
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Kankeleit
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Gütlich
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Ming
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Renz
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Wdowiak
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Squyres
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Arvidson
D005118:Extraterrestrial Environment; D005290:Ferric Compounds; D052203:Ferrosoferric Oxide; D019015:Geologic Sediments; D007501:Iron; D058085:Iron Compounds; D017616:Magnesium Compounds; D018535:Mars; D008903:Minerals; D010087:Oxides; D017640:Silicates; D015204:Spectroscopy, Mossbauer
D005290:Ferric Compounds; D058085:Iron Compounds; D017616:Magnesium Compounds; D008903:Minerals; D010087:Oxides; D017640:Silicates; C092478:pyroxene; C000499:ferric oxide; C034475:olivine; D007501:Iron; D052203:Ferrosoferric Oxide