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Mineralogy on Mars at Gusev Crater and Meridiani Planum as seen by Iron Mössbauer spectroscopy
Goldschmidt Conference Abstracts 2006
Mineralogy on Mars at Gusev Crater and Meridiani Planum as seen by Iron Mo¨ssbauer spectroscopy
A325
Multi-proxy relationships in foraminiferal tests as delineated from element–element plots of time-resolved flo-thru data
G. KLINGELHO¨FER1, R.V. MORRIS2, A.S. YEN3, D.W. MING2, CH. SCHRO¨DER1, D. RODIONOV1
GARY P. KLINKHAMMER1, BRIAN A.
HALEY
2
1 1
Institute of Inorganic and Analytical Chemistry, University Mainz, Germany ([email protected]) 2 NASA Johnson Space Center, Houston, TX, USA (richard.v. [email protected]; [email protected]) 3 Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, USA The Mars Exploration Rovers Spirit and Opportunity have explored the Martian surface at Gusev Crater and Meridiani Planum for more than two Earth years. More than 15 different minerals have been identified so far by the Mo¨ssbauer instruments on board the two rovers (Morris et al., 2004; Klingelho¨fer et al., 2004; Morris et al., 2006). Mo¨ssbauer spectroscopy identified the secondary Fe3+-bearing minerals jarosite, hematite, and nanophase iron oxides in the sulfate-rich outcrop rocks at Meridiani Planum (Klingelho¨fer et al., 2004). Pyroxene may be a remnant primary Fe2+-bearing mineral. No precursor material to the sulfate-rich outcrop has been identified to date, but it has been inferred to be basaltic in composition (McLennan et al., 2005; Tosca et al., 2005). At Gusev Crater rocks are much more diverse, ranging from little altered basaltic material in the plains to pervasively altered basalt in the Columbia Hills (Morris et al., 2006; Ming et al., 2006). Primary minerals include the Fe2+-bearing minerals olivine, pyroxene, and ilmenite, as well as the mixed-valence iron oxide magnetite. Secondary minerals include the Fe3+-bearing minerals hematite, goethite, nanophase iron oxides, and an unspecified iron sulfate phase. The relation between primary and secondary minerals varies over short spatial scales. In particular the minerals jarosite and goethite found at Meridiani Planum and Gusev Crater, respectively, are clear mineralogical evidence for aqueous weathering processes active at both landing sites in the past. New results will be reported. Recent results from Gusev Crater indicate the presence of hematite in greater abundance than in many targets at Meridiani. Possible explanations for weathering scenarious will be given.
Oregon State University, COAS, Ocean Admin Bldg. 104, Corvallis, OR, USA ([email protected]) 2 Leibniz-Institute Marine Sciences, IFM-GEOMAR, East Shore Campus, Wischhofstra. 1-3, Kiel, Germany ([email protected]) Flo-Thru Time Resolved Analysis (FT-TRA) provides a spectrum of element (El) to calcium ratios for every sample. A typical FT analysis produces >7000 El/Ca ratios per proxy (compared to 1 from the traditional cleaning/dissolution technique), and sorts these ratios by phase solubility. One benefit of this approach is seen in examination of El–El relationships in the dissolution spectra. By definition, homogeneous samples display linear El–Ca correlations with zero intercepts and scatter equivalent to analytical precision. These features of homegeneity are seen in flo-thru results from carbonate standards. However, El–El relationships in foram samples can be complex resulting from the presence of multiple biogenic and abiotic phases (see figure). This study examines Mg/Ca, Sr/Ca, Ba/Ca, and Mn/Ca ratios in samples of G. ruber and G. dutertrei from ODP site 1242 and piston core Y69-71P from the Panama Basin and Easter Equatorial Pacific, respectively. Many of the Mn dissolution profiles have maxima after Ca, suggesting that these samples are overgrown by secondary Mn-rich carbonate, probably rhodochrosite (MnCO3). Secondary Ba peaks are even more pervasive, suggesting that biogenic carbonate may be a significant carrier of labile Ba to the sea floor in the form of BaCO3 (witherite) or highly substituted barite. We will show how Ba–Ca and Mn–Ca relationships from FTTRA can be used to isolate pristine biogenic calcite from altered material, and further investigate the use of thir El/Ca ratios as paleoproxies.
References Klingelho¨fer, G. et al., 2004. Science 306, 1740–1745. McLennan, S.M. et al., 2005. EPSL 240, 95–121. Ming, D.W. et al., 2006. J. Geophys. Res. 111, E02S12. doi:10.1029/ 2005JE002560. Morris, R.V. et al., 2004. Science 305, 833–836. Morris, R.V. et al., 2006. JGR 111, E02S13. Tosca, N.J. et al., 2005. EPSL 240, 122–148. doi:10.1016/j.gca.2006.06.656
doi:10.1016/j.gca.2006.06.657
Mineralogy on Mars at Gusev Crater and Meridiani Planum as seen by Iron Mo¨ssbauer spectroscopy
A325
Multi-proxy relationships in foraminiferal tests as delineated from element–element plots of time-resolved flo-thru data
G. KLINGELHO¨FER1, R.V. MORRIS2, A.S. YEN3, D.W. MING2, CH. SCHRO¨DER1, D. RODIONOV1
GARY P. KLINKHAMMER1, BRIAN A.
HALEY
2
1 1
Institute of Inorganic and Analytical Chemistry, University Mainz, Germany ([email protected]) 2 NASA Johnson Space Center, Houston, TX, USA (richard.v. [email protected]; [email protected]) 3 Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, USA The Mars Exploration Rovers Spirit and Opportunity have explored the Martian surface at Gusev Crater and Meridiani Planum for more than two Earth years. More than 15 different minerals have been identified so far by the Mo¨ssbauer instruments on board the two rovers (Morris et al., 2004; Klingelho¨fer et al., 2004; Morris et al., 2006). Mo¨ssbauer spectroscopy identified the secondary Fe3+-bearing minerals jarosite, hematite, and nanophase iron oxides in the sulfate-rich outcrop rocks at Meridiani Planum (Klingelho¨fer et al., 2004). Pyroxene may be a remnant primary Fe2+-bearing mineral. No precursor material to the sulfate-rich outcrop has been identified to date, but it has been inferred to be basaltic in composition (McLennan et al., 2005; Tosca et al., 2005). At Gusev Crater rocks are much more diverse, ranging from little altered basaltic material in the plains to pervasively altered basalt in the Columbia Hills (Morris et al., 2006; Ming et al., 2006). Primary minerals include the Fe2+-bearing minerals olivine, pyroxene, and ilmenite, as well as the mixed-valence iron oxide magnetite. Secondary minerals include the Fe3+-bearing minerals hematite, goethite, nanophase iron oxides, and an unspecified iron sulfate phase. The relation between primary and secondary minerals varies over short spatial scales. In particular the minerals jarosite and goethite found at Meridiani Planum and Gusev Crater, respectively, are clear mineralogical evidence for aqueous weathering processes active at both landing sites in the past. New results will be reported. Recent results from Gusev Crater indicate the presence of hematite in greater abundance than in many targets at Meridiani. Possible explanations for weathering scenarious will be given.
Oregon State University, COAS, Ocean Admin Bldg. 104, Corvallis, OR, USA ([email protected]) 2 Leibniz-Institute Marine Sciences, IFM-GEOMAR, East Shore Campus, Wischhofstra. 1-3, Kiel, Germany ([email protected]) Flo-Thru Time Resolved Analysis (FT-TRA) provides a spectrum of element (El) to calcium ratios for every sample. A typical FT analysis produces >7000 El/Ca ratios per proxy (compared to 1 from the traditional cleaning/dissolution technique), and sorts these ratios by phase solubility. One benefit of this approach is seen in examination of El–El relationships in the dissolution spectra. By definition, homogeneous samples display linear El–Ca correlations with zero intercepts and scatter equivalent to analytical precision. These features of homegeneity are seen in flo-thru results from carbonate standards. However, El–El relationships in foram samples can be complex resulting from the presence of multiple biogenic and abiotic phases (see figure). This study examines Mg/Ca, Sr/Ca, Ba/Ca, and Mn/Ca ratios in samples of G. ruber and G. dutertrei from ODP site 1242 and piston core Y69-71P from the Panama Basin and Easter Equatorial Pacific, respectively. Many of the Mn dissolution profiles have maxima after Ca, suggesting that these samples are overgrown by secondary Mn-rich carbonate, probably rhodochrosite (MnCO3). Secondary Ba peaks are even more pervasive, suggesting that biogenic carbonate may be a significant carrier of labile Ba to the sea floor in the form of BaCO3 (witherite) or highly substituted barite. We will show how Ba–Ca and Mn–Ca relationships from FTTRA can be used to isolate pristine biogenic calcite from altered material, and further investigate the use of thir El/Ca ratios as paleoproxies.
References Klingelho¨fer, G. et al., 2004. Science 306, 1740–1745. McLennan, S.M. et al., 2005. EPSL 240, 95–121. Ming, D.W. et al., 2006. J. Geophys. Res. 111, E02S12. doi:10.1029/ 2005JE002560. Morris, R.V. et al., 2004. Science 305, 833–836. Morris, R.V. et al., 2006. JGR 111, E02S13. Tosca, N.J. et al., 2005. EPSL 240, 122–148. doi:10.1016/j.gca.2006.06.656
doi:10.1016/j.gca.2006.06.657