Stability of hydrous minerals on the martian surface

Bish, David L.; Carey, J. William; Vaniman, D. T.; Chipera, S. J.

doi:10.1016/s0019-1035(03)00140-4

Cited by 126 publications

(107 citation statements)

References 30 publications

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“…Clay minerals are soft, and many gain or lose water as humidity changes, swelling or contracting in the process. Studies of smectite hydration at Mars surface conditions indicate that swelling cycles may occur on a daily basis (Bish et al 2003). Most sulfate minerals are also soft and many occur in varying hydration states that also change with temperature and humidity.…”

Section: Preparation Methods and Selection Of Target Compositionsmentioning

confidence: 99%

Ceramic ChemCam Calibration Targets on Mars Science Laboratory

et al. 2012

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The ChemCam instrument on the Mars Science Laboratory rover Curiosity will use laser-induced breakdown spectroscopy (LIBS) to analyze major and minor element chemistry from sub-millimeter spot sizes, at ranges of ∼1.5-7 m. To interpret the emission spectra obtained, ten calibration standards will be carried on the rover deck. Graphite, Ti metal, and four glasses of igneous composition provide primary, homogeneous calibration targets for the laser. Four granular ceramic targets have been added to provide compositions closer to soils and sedimentary materials like those expected at the Gale Crater field site on Mars. Components used in making these ceramics include basalt, evaporite, and phyllosilicate materials that approximate the chemical compositions of detrital and authigenic constituents of clastic and evaporite sediments, including the elevated sulfate contents present in many Mars sediments and soils. Powdered components were sintered at low temperature (800°C) with a small amount (9 wt.%) of lithium tetraborate flux to produce ceramics that retain volatile sulfur yet are durable enough for the mission. The ceramic targets are more heterogeneous than the pure element and homogenous glass standards but they provide standards with compositions more similar to the sedimentary rocks that will be Curiosity's prime targets at Gale Crater.

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Section: Preparation Methods and Selection Of Target Compositionsmentioning

confidence: 99%

Ceramic ChemCam Calibration Targets on Mars Science Laboratory

et al. 2012

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“…The surface of Mars currently has a very thin atmosphere, but the possibility of mineral surface hydration under Martian conditions was investigated in the laboratory (12,13) and recently detected directly at Gale Crater, Mars (14). There are great diurnal temperature differences and sheltered basins with subsequent transient melting of ice (15)(16)(17) and craters where the atmospheric pressure is higher than average (18,19).…”

Section: Discussion: Geochemical and Technological Implicationsmentioning

confidence: 99%

Rapidly reversible redox transformation in nanophase manganese oxides at room temperature triggered by changes in hydration

Birkner

Navrotsky

2014

Proc. Natl. Acad. Sci. U.S.A.

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Chemisorption of water onto anhydrous nanophase manganese oxide surfaces promotes rapidly reversible redox phase changes as confirmed by calorimetry, X-ray diffraction, and titration for manganese average oxidation state. Surface reduction of bixbyite (Mn 2 O 3 ) to hausmannite (Mn 3 O 4 ) occurs in nanoparticles under conditions where no such reactions are seen or expected on grounds of bulk thermodynamics in coarse-grained materials. Additionally, transformation does not occur on nanosurfaces passivated by at least 2% coverage of what is likely an amorphous manganese oxide layer. The transformation is due to thermodynamic control arising from differences in surface energies of the two phases (Mn 2 O 3 and Mn 3 O 4 ) under wet and dry conditions. Such reversible and rapid transformation near room temperature may affect the behavior of manganese oxides in technological applications and in geologic and environmental settings.phase transformation | oxidation/reduction | water adsorption/desorption M anganese oxides are ubiquitous in the natural environment, often occurring as very fine grained (nanopahase) precipitates and coatings, and also find numerous technological applications, especially in catalysis. Easy variation of manganese oxidation state (Mn 2+ , Mn 3+ , Mn 4+ ) lends complexity to phase behavior and physical and chemical properties of manganese oxides. The thermodynamic stability of manganese oxide nanoparticles helps determine the robustness of such oxides and their behavior in soils and larger-scale geochemical cycles, as well as in applications in catalysis, renewable energy, and environmental remediation. The structure and energetics of nanoparticle surfaces are influenced by the phase present and its oxidation state and by the extent of surface hydration; thus dry surfaces are structurally and thermodynamically distinct from hydrated surfaces (1, 2). Using Mn 3 O 4 (hausmannite), Mn 2 O 3 (bixbyite), and MnO 2 (pyrolusite), previously, we showed that the position in temperature−oxygen fugacity space, of oxidation−reduction (redox) phase equilibria, is shifted at the nanoscale due to differences in nanophase surface energy as a function of particle size and surface hydration and that this thermodynamic shift is in favor of the lower surface energy phase (3). In the manganese oxides, the surface energy increases in the order hausmannite, bixbyite, pyrolusite, so small particle size favors the more reduced oxide phase.This paper summarizes observations in the nanoscale Mn 2 O 3 − Mn 3 O 4 system, which is found to undergo rapidly reversible redox phase transformations at room temperature induced by the adsorption/desorption of surface water. It is expected that the degree of reduction is a function of both average particle size and particle size distribution, but this work focuses on only one representative material to provide proof of concept. The rapid response of activated surfaces to changing hydration condition implies thermodynamic control and has implications for geochemistry, planetary scie...

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“…Salt hydrates could also explain the observations as they have Scott and Tanaka (1986). up to 50 wt. % WEH, but their stability in the Martian regolith has not been demonstrated (Bish et al, 2003). No detections of hydrated minerals within the MFF are reported in either CRISM or OMEGA data sets .…”

Section: The Medusae Fossae Formation: Ice or Dry Porous Rock?mentioning

confidence: 94%

Equatorial locations of water on Mars: Improved resolution maps based on Mars Odyssey Neutron Spectrometer data

Wilson

Eke

Massey

et al. 2018

Icarus

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We present a map of the near subsurface hydrogen distribution on Mars, based on epithermal neutron data from the Mars Odyssey Neutron Spectrometer. The map's spatial resolution is approximately improved two-fold via a new form of the pixon image reconstruction technique. We discover hydrogen-rich mineralogy far from the poles, including ∼10 wt. % water equivalent hydrogen (WEH) on the flanks of the Tharsis Montes and >40 wt. % WEH at the Medusae Fossae Formation (MFF). The high WEH abundance at the MFF implies the presence of bulk water ice. This supports the hypothesis of recent periods of high orbital obliquity during which water ice was stable on the surface. We find the young undivided channel system material in southern Elysium Planitia to be distinct from its surroundings and exceptionally dry; there is no evidence of hydration at the location in Elysium Planitia suggested to contain a buried water ice sea. Finally, we find that the sites of recurring slope lineae (RSL) do not correlate with subsurface hydration. This implies that RSL are not fed by large, near-subsurface aquifers, but are instead the result of either small (<120 km diameter) aquifers, deliquescence of perchlorate and chlorate salts or dry, granular flows.

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Stability of hydrous minerals on the martian surface

Cited by 126 publications

References 30 publications

Ceramic ChemCam Calibration Targets on Mars Science Laboratory

Ceramic ChemCam Calibration Targets on Mars Science Laboratory

Rapidly reversible redox transformation in nanophase manganese oxides at room temperature triggered by changes in hydration

Equatorial locations of water on Mars: Improved resolution maps based on Mars Odyssey Neutron Spectrometer data

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