TY - JOUR
T1 - Iron Mobility During Diagenesis at Vera Rubin Ridge, Gale Crater, Mars
AU - L'Haridon, J.
AU - Mangold, N.
AU - Fraeman, A. A.
AU - Johnson, J. R.
AU - Cousin, A.
AU - Rapin, W.
AU - David, G.
AU - Dehouck, E.
AU - Sun, V.
AU - Frydenvang, J.
AU - Gasnault, O.
AU - Gasda, P.
AU - Lanza, N.
AU - Forni, O.
AU - Meslin, P. Y.
AU - Schwenzer, S. P.
AU - Bridges, J.
AU - Horgan, B.
AU - House, C. H.
AU - Salvatore, M.
AU - Maurice, S.
AU - Wiens, R. C.
N1 - Funding Information:
We are indebted to the Mars Science Laboratory Project engineering and science teams for their participations in tactical and strategic operations. All data used in this study are accessible at the Planetary Data System ( http://pds‐geosciences.wustl.edu/missions/msl/index.htm ). Data provided by the ChemCam instrument are supported in the United States by NASA's Mars Exploration Program and in France by the Centre National d'Etudes Spatiales (CNES) and the Agence Nationale de la Recherche (ANR) under the program ANR‐16‐CE31‐0012 entitled “Mars‐Prime.” J. Frydenvang acknowledges the support of the Carlsberg Foundation.
Funding Information:
We are indebted to the Mars Science Laboratory Project engineering and science teams for their participations in tactical and strategic operations. All data used in this study are accessible at the Planetary Data System (http://pds-geosciences.wustl.edu/missions/msl/index.htm). Data provided by the ChemCam instrument are supported in the United States by NASA's Mars Exploration Program and in France by the Centre National d'Etudes Spatiales (CNES) and the Agence Nationale de la Recherche (ANR) under the program ANR-16-CE31-0012 entitled ?Mars-Prime.? J. Frydenvang acknowledges the support of the Carlsberg Foundation.
Publisher Copyright:
©2020. American Geophysical Union. All Rights Reserved.
PY - 2020/11
Y1 - 2020/11
N2 - The Curiosity rover investigated a topographic structure known as Vera Rubin ridge, associated with a hematite signature in orbital spectra. There, Curiosity encountered mudstones interpreted as lacustrine deposits, conformably overlying the 300 m-thick underlying sedimentary rocks of the Murray formation at the base of Mount Sharp. While the presence of hematite (α-Fe2O3) was confirmed in situ by both Mastcam and ChemCam spectral observations and by the CheMin instrument, neither ChemCam nor APXS observed any significant increase in FeOT (total iron oxide) abundances compared to the rest of the Murray formation. Instead, Curiosity discovered dark-toned diagenetic features displaying anomalously high FeOT abundances, commonly observed in association with light-toned Ca-sulfate veins but also as crystal pseudomorphs in the host rock. These iron-rich diagenetic features are predominantly observed in “gray” outcrops on the upper part of the ridge, which lack the telltale ferric signature of other Vera Rubin ridge outcrops. Their composition is consistent with anhydrous Fe-oxide, as the enrichment in iron is not associated with enrichment in any other elements, nor with detections of volatiles. The lack of ferric absorption features in the ChemCam reflectance spectra and the hexagonal crystalline structure associated with dark-toned crystals points toward coarse “gray” hematite. In addition, the host rock adjacent to these features appears bleached and shows low-FeOT content as well as depletion in Mn, indicating mobilization of these redox-sensitive elements during diagenesis. Thus, groundwater fluid circulations could account for the remobilization of iron and recrystallization as crystalline hematite during diagenesis on Vera Rubin ridge.
AB - The Curiosity rover investigated a topographic structure known as Vera Rubin ridge, associated with a hematite signature in orbital spectra. There, Curiosity encountered mudstones interpreted as lacustrine deposits, conformably overlying the 300 m-thick underlying sedimentary rocks of the Murray formation at the base of Mount Sharp. While the presence of hematite (α-Fe2O3) was confirmed in situ by both Mastcam and ChemCam spectral observations and by the CheMin instrument, neither ChemCam nor APXS observed any significant increase in FeOT (total iron oxide) abundances compared to the rest of the Murray formation. Instead, Curiosity discovered dark-toned diagenetic features displaying anomalously high FeOT abundances, commonly observed in association with light-toned Ca-sulfate veins but also as crystal pseudomorphs in the host rock. These iron-rich diagenetic features are predominantly observed in “gray” outcrops on the upper part of the ridge, which lack the telltale ferric signature of other Vera Rubin ridge outcrops. Their composition is consistent with anhydrous Fe-oxide, as the enrichment in iron is not associated with enrichment in any other elements, nor with detections of volatiles. The lack of ferric absorption features in the ChemCam reflectance spectra and the hexagonal crystalline structure associated with dark-toned crystals points toward coarse “gray” hematite. In addition, the host rock adjacent to these features appears bleached and shows low-FeOT content as well as depletion in Mn, indicating mobilization of these redox-sensitive elements during diagenesis. Thus, groundwater fluid circulations could account for the remobilization of iron and recrystallization as crystalline hematite during diagenesis on Vera Rubin ridge.
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U2 - 10.1029/2019JE006299
DO - 10.1029/2019JE006299
M3 - Article
AN - SCOPUS:85091674523
VL - 125
JO - Journal of Geophysical Research: Planets
JF - Journal of Geophysical Research: Planets
SN - 2169-9097
IS - 11
M1 - e2019JE006299
ER -