The potassic sedimentary rocks in Gale Crater, Mars, as seen by ChemCam on board Curiosity
Creators
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Le Deit, L.1
- Mangold, N.1
- Forni, O.2
- Cousin, A.2
- Lasue, J.2
- Schröder, S.2, 3
- Wiens, R. C.4
- Sumner, D.5
- Fabre, C.6
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Stack, K. M.7
- Anderson, R. B.8
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Blaney, D.7
- Clegg, S.4
- Dromart, G.9
- Fisk, M.10
- Gasnault, O.2
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Grotzinger, J. P.11
- Gupta, S.12
- Lanza, N.4
- Le Mouélic, S.1
- Maurice, S.2
- McLennan, S. M.13
- Meslin, P.-Y.2
- Nachon, M.1
- Newsom, H.14
- Payré, V.6
- Rapin, W.2
- Rice, M.15
- Sautter, V.16
- Treiman, A. H.17
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1.
Laboratoire de Planétologie et Géodynamique de Nantes
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2.
Research Institute in Astrophysics and Planetology
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3.
German Aerospace Center
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4.
Los Alamos National Laboratory
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5.
University of California, Davis
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6.
University of Lorraine
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7.
Jet Propulsion Lab
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8.
Astrogeology Science Center
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9.
École Normale Supérieure de Lyon
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10.
Oregon State University
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11.
California Institute of Technology
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12.
Imperial College London
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13.
Stony Brook University
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14.
University of New Mexico
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15.
Western Washington University
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16.
Laboratoire de Minéralogie & Cosmochimie du Muséum
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17.
Lunar and Planetary Institute
Abstract
The Mars Science Laboratory rover Curiosity encountered potassium‐rich clastic sedimentary rocks at two sites in Gale Crater, the waypoints Cooperstown and Kimberley. These rocks include several distinct meters thick sedimentary outcrops ranging from fine sandstone to conglomerate, interpreted to record an ancient fluvial or fluvio‐deltaic depositional system. From ChemCam Laser‐Induced Breakdown Spectroscopy (LIBS) chemical analyses, this suite of sedimentary rocks has an overall mean K₂O abundance that is more than 5 times higher than that of the average Martian crust. The combined analysis of ChemCam data with stratigraphic and geographic locations reveals that the mean K₂O abundance increases upward through the stratigraphic section. Chemical analyses across each unit can be represented as mixtures of several distinct chemical components, i.e., mineral phases, including K‐bearing minerals, mafic silicates, Fe‐oxides, and Fe‐hydroxide/oxyhydroxides. Possible K‐bearing minerals include alkali feldspar (including anorthoclase and sanidine) and K‐bearing phyllosilicate such as illite. Mixtures of different source rocks, including a potassium‐rich rock located on the rim and walls of Gale Crater, are the likely origin of observed chemical variations within each unit. Physical sorting may have also played a role in the enrichment in K in the Kimberley formation. The occurrence of these potassic sedimentary rocks provides additional evidence for the chemical diversity of the crust exposed at Gale Crater.
Additional Information
© 2016 American Geophysical Union. Issue Online: 11 June 2016; Version of Record online: 13 May 2016; Manuscript accepted: 30 March 2016; Manuscript revised: 07 March 2016; Manuscript received: 11 December 2015. This work is supported by the Centre National d'Études Spatiales (CNES), France, and by the NASA Mars Program Office. We gratefully thank the Curiosity rover operation team at Jet Propulsion Laboratory for the success of this mission. We also thank Jeff Taylor, our anonymous reviewer, and associate editor for their very thoughtful and thorough comments that greatly improved the manuscript. Imaging and chemical data presented here are available in the NASA Planetary Data System (PDS) http://pds‐geosciences.wustl.edu/missions/msl.Attached Files
Published - 2015JE004987.pdf
Files
2015JE004987.pdf
Additional details
Identifiers
- Eprint ID
- 105218
- Resolver ID
- CaltechAUTHORS:20200902-124645501
Funding
- Centre National d'Études Spatiales (CNES)
- NASA
Dates
- Created
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2020-09-08Created from EPrint's datestamp field
- Updated
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2021-11-16Created from EPrint's last_modified field
Caltech Custom Metadata
- Caltech groups
- Division of Geological and Planetary Sciences (GPS)