NASA Logo

NTRS

NTRS - NASA Technical Reports Server

Back to Results
Moessbauer 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 HillsThe Moessbauer 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 Fe(3+)-sulfate. Adirondack basaltic rocks on the plains are nearly unaltered (Fe(3+)/Fe(sub 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 Fe(3+)/Fe(sub T) approx.0.6-0.9). Fe from pyroxene is greater than Fe from olivine (Ol sometimes absent), and Fe(2+) from Ol+Px is 40-49% and 9-24% for moderately and pervasively altered materials, respectively. Ilmenite (Fe from Ilm approx.3-6%) is present in Backstay, Wishstone, Keystone, and related rocks along with magnetite (Fe from Mt approx. 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 (alpha-FeOOH) is mineralogical evidence for aqueous processes because it has structural hydroxide and is formed under aqueous conditions. Relatively unaltered basaltic soils (Fe(3+)/Fe(sub T) approx. 0.3) occur throughout Gusev crater (approx. 60-80% Fe from Ol+Px, approx. 10-30% from npOx, and approx. 10% from Mt). PasoRobles soil in the Columbia Hills has a unique occurrence of high concentrations of Fe(3+)-sulfate (approx. 65% of Fe). Magnetite is identified as a strongly magnetic phase in Martian soil and dust.
Document ID
20080030169
Acquisition Source
Johnson Space Center
Document Type
Preprint (Draft being sent to journal)
Authors
Morris, R. V.
(NASA Johnson Space Center Houston, TX, United States)
Klingelhoefer, G.
(Mainz Univ. Germany)
Schroeder, C.
(Mainz Univ. Germany)
Rodionov, D. S.
(Mainz Univ. Germany)
Yen, A.
(Jet Propulsion Lab., California Inst. of Tech. Pasadena, CA, United States)
Ming, D. W.
(NASA Johnson Space Center Houston, TX, United States)
deSouza, P. A., Jr.
(Mainz Univ. Germany)
Fleischer, I.
(Mainz Univ. Germany)
Wdowiak, T.
(Alabama Univ. Birmingham, AL, United States)
Gellert, R.
(Guelph Univ. Ontario, Canada)
Bernhardt, B.
(Mainz Univ. Germany)
Evlanov, E. N.
(Academy of Sciences (USSR) Moscow, Russian Federation)
Zubkov, B.
(Academy of Sciences (USSR) Moscow, Russian Federation)
Foh, J.
(Mainz Univ. Germany)
Bonnes, U.
(Darmstadt Univ. of Tech. Darmstadt, Germany)
Kankeleit, E.
(Darmstadt Univ. of Tech. Darmstadt, Germany)
Guetlich, P.
(Mainz Univ. Germany)
Renz, F.
(Mainz Univ. Germany)
Squyres, S. W.
(Cornell Univ. Ithaca, NY, United States)
Arvidson, R. E.
(Washington Univ. Saint Louis, MO, United States)
Date Acquired
August 24, 2013
Publication Date
January 1, 2006
Subject Category
Geophysics
Funding Number(s)
CONTRACT_GRANT: CAPES PASJ 142/1999
CONTRACT_GRANT: GSA 50QM 99022
WBS: WBS 361425.94.95
Distribution Limits
Public
Copyright
Public Use Permitted.
No Preview Available