@article{a7dad5e3840b45d2aa9c472ee9cb0802,
title = "Chemical alteration of fine-grained sedimentary rocks at Gale crater",
abstract = "From Sol 750 to 1550, the Curiosity rover documented>100 m thick stack of fine-grained sedimentary rocks making up part of the Murray formation, at the base of Mt Sharp, Gale crater. Here, we use data collected by the ChemCam instrument to estimate the level of chemical weathering in these sedimentary rocks. Both the Chemical Index of Alteration (CIA) and the Weathering Index Scale (WIS) indicate a progressive increase in alteration up section, reaching values of CIA of 63 and WIS of 25%. The increase in CIA and WIS values is coupled with a decrease in calcium abundance, suggesting partial dissolution of Ca-bearing minerals (clinopyroxene and plagioclase). Mineralogy from the CheMin X-ray diffraction instrument indicates a decrease in mafic minerals compared with previously analyzed strata and a significant proportion of phyllosilicates consistent with this interpretation. These observations suggest that the sediments were predominantly altered in an open system, before or during their emplacement, contrasting with the rock-dominated conditions inferred in sedimentary deposits analyzed at Yellowknife Bay.",
author = "N. Mangold and E. Dehouck and C. Fedo and O. Forni and C. Achilles and T. Bristow and Downs, {R. T.} and J. Frydenvang and O. Gasnault and J. L'Haridon and {Le Deit}, L. and S. Maurice and McLennan, {S. M.} and Meslin, {P. Y.} and S. Morrison and Newsom, {H. E.} and E. Rampe and W. Rapin and F. Rivera-Hernandez and M. Salvatore and Wiens, {R. C.}",
note = "Funding Information: We acknowledge the two reviewers for their insightful comments. This research was carried out with funding from the Centre National d'Etudes Spatiales (CNES) and the Agence Nationale de la Recherche (ANR) under the program ANR-16-CE31-0012 entitled ʺMars-Primeʺ. Work in the United States was carried out under contract from NASA's Mars Program Office. The data reported in this paper are archived at the Planetary Data System, accessible at http://pds-geosciences.wustl.edu/missions/msl/index.htm . J.F. acknowledges the support from the Carlsberg Foundation . Author contributions: N.M. analyzed ChemCam data and wrote the text. E.D., C.F., S.M.M and M.S. provided input on stratigraphy and alteration indices on Earth. E.D., O.F. J.F., O.G., J.H., L.L.D., S.M., P.M., H.E.N., W.R., F.R-H, R.W participated in ChemCam data acquisition and processing. C.A, T.B., S.M., E.R., R.D participated to the processing and analyses of CheMin data. Publisher Copyright: {\textcopyright} 2018 Elsevier Inc.",
year = "2019",
month = mar,
day = "15",
doi = "10.1016/j.icarus.2018.11.004",
language = "English (US)",
volume = "321",
pages = "619--631",
journal = "Icarus",
issn = "0019-1035",
publisher = "Academic Press Inc.",
}