Discordant K-Ar and Young Exposure Dates for the Windjana sandstone, Kimberley, Gale Crater, Mars
K-Ar and noble gas surface exposure age measurements were carried out on the Windjana sandstone, Kimberley region, Gale Crater, Mars, by using the Sample Analysis at Mars instrument on the Curiosity rover. The sandstone is unusually rich in sanidine, as determined by CheMin X-ray diffraction, contri...
Published in: | Journal of Geophysical Research: Planets |
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American Geophysical Union
2016
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ftcaltechauth:oai:authors.library.caltech.edu:71199 2023-05-15T18:45:43+02:00 Discordant K-Ar and Young Exposure Dates for the Windjana sandstone, Kimberley, Gale Crater, Mars Vasconcelos, P. M. Farley, K. A. Malespin, C. A. Mahaffy, P. Ming, D. McLennan, S. M. Hurowitz, J. A. Rice, Melissa S. 2016-10 application/pdf https://authors.library.caltech.edu/71199/ https://authors.library.caltech.edu/71199/2/Vasconcelos_et_al-2016-Journal_of_Geophysical_Research__Planets.pdf https://authors.library.caltech.edu/71199/1/jgre20600.pdf https://resolver.caltech.edu/CaltechAUTHORS:20161018-073743780 en eng American Geophysical Union https://authors.library.caltech.edu/71199/2/Vasconcelos_et_al-2016-Journal_of_Geophysical_Research__Planets.pdf https://authors.library.caltech.edu/71199/1/jgre20600.pdf Vasconcelos, P. M. and Farley, K. A. and Malespin, C. A. and Mahaffy, P. and Ming, D. and McLennan, S. M. and Hurowitz, J. A. and Rice, Melissa S. (2016) Discordant K-Ar and Young Exposure Dates for the Windjana sandstone, Kimberley, Gale Crater, Mars. Journal of Geophysical Research. Planets, 121 (10). pp. 2176-2192. ISSN 2169-9097. doi:10.1002/2016JE005017. https://resolver.caltech.edu/CaltechAUTHORS:20161018-073743780 <https://resolver.caltech.edu/CaltechAUTHORS:20161018-073743780> other Article PeerReviewed 2016 ftcaltechauth https://doi.org/10.1002/2016JE005017 2021-11-18T18:39:22Z K-Ar and noble gas surface exposure age measurements were carried out on the Windjana sandstone, Kimberley region, Gale Crater, Mars, by using the Sample Analysis at Mars instrument on the Curiosity rover. The sandstone is unusually rich in sanidine, as determined by CheMin X-ray diffraction, contributing to the high K_2O concentration of 3.09 ± 0.20 wt % measured by Alpha-Particle X-ray Spectrometer analysis. A sandstone aliquot heated to ~915°C yielded a K-Ar age of 627 ± 50 Ma. Reheating this aliquot yielded no additional Ar. A second aliquot heated in the same way yielded a much higher K-Ar age of 1710 ± 110 Ma. These data suggest incomplete Ar extraction from a rock with a K-Ar age older than 1710 Ma. Incomplete extraction at ~900°C is not surprising for a rock with a large fraction of K carried by Ar-retentive K-feldspar. Likely, variability in the exact temperature achieved by the sample from run to run, uncertainties in sample mass estimation, and possible mineral fractionation during transport and storage prior to analysis may contribute to these discrepant data. Cosmic ray exposure ages from ^3He and ^(21)Ne in the two aliquots are minimum values given the possibility of incomplete extraction. However, the general similarity between the ^3He (57 ± 49 and 18 ± 32 Ma, mean 30 Ma) and ^(21)Ne (2 ± 32 and 83 ± 24 Ma, mean 54 Ma) exposure ages provides no evidence for underextraction. The implied erosion rate at the Kimberley location is similar to that reported at the nearby Yellowknife Bay outcrop. Article in Journal/Newspaper Yellowknife Caltech Authors (California Institute of Technology) Yellowknife Yellowknife Bay ENVELOPE(-114.336,-114.336,62.367,62.367) Journal of Geophysical Research: Planets 121 10 2176 2192 |
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Open Polar |
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Caltech Authors (California Institute of Technology) |
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ftcaltechauth |
language |
English |
description |
K-Ar and noble gas surface exposure age measurements were carried out on the Windjana sandstone, Kimberley region, Gale Crater, Mars, by using the Sample Analysis at Mars instrument on the Curiosity rover. The sandstone is unusually rich in sanidine, as determined by CheMin X-ray diffraction, contributing to the high K_2O concentration of 3.09 ± 0.20 wt % measured by Alpha-Particle X-ray Spectrometer analysis. A sandstone aliquot heated to ~915°C yielded a K-Ar age of 627 ± 50 Ma. Reheating this aliquot yielded no additional Ar. A second aliquot heated in the same way yielded a much higher K-Ar age of 1710 ± 110 Ma. These data suggest incomplete Ar extraction from a rock with a K-Ar age older than 1710 Ma. Incomplete extraction at ~900°C is not surprising for a rock with a large fraction of K carried by Ar-retentive K-feldspar. Likely, variability in the exact temperature achieved by the sample from run to run, uncertainties in sample mass estimation, and possible mineral fractionation during transport and storage prior to analysis may contribute to these discrepant data. Cosmic ray exposure ages from ^3He and ^(21)Ne in the two aliquots are minimum values given the possibility of incomplete extraction. However, the general similarity between the ^3He (57 ± 49 and 18 ± 32 Ma, mean 30 Ma) and ^(21)Ne (2 ± 32 and 83 ± 24 Ma, mean 54 Ma) exposure ages provides no evidence for underextraction. The implied erosion rate at the Kimberley location is similar to that reported at the nearby Yellowknife Bay outcrop. |
format |
Article in Journal/Newspaper |
author |
Vasconcelos, P. M. Farley, K. A. Malespin, C. A. Mahaffy, P. Ming, D. McLennan, S. M. Hurowitz, J. A. Rice, Melissa S. |
spellingShingle |
Vasconcelos, P. M. Farley, K. A. Malespin, C. A. Mahaffy, P. Ming, D. McLennan, S. M. Hurowitz, J. A. Rice, Melissa S. Discordant K-Ar and Young Exposure Dates for the Windjana sandstone, Kimberley, Gale Crater, Mars |
author_facet |
Vasconcelos, P. M. Farley, K. A. Malespin, C. A. Mahaffy, P. Ming, D. McLennan, S. M. Hurowitz, J. A. Rice, Melissa S. |
author_sort |
Vasconcelos, P. M. |
title |
Discordant K-Ar and Young Exposure Dates for the Windjana sandstone, Kimberley, Gale Crater, Mars |
title_short |
Discordant K-Ar and Young Exposure Dates for the Windjana sandstone, Kimberley, Gale Crater, Mars |
title_full |
Discordant K-Ar and Young Exposure Dates for the Windjana sandstone, Kimberley, Gale Crater, Mars |
title_fullStr |
Discordant K-Ar and Young Exposure Dates for the Windjana sandstone, Kimberley, Gale Crater, Mars |
title_full_unstemmed |
Discordant K-Ar and Young Exposure Dates for the Windjana sandstone, Kimberley, Gale Crater, Mars |
title_sort |
discordant k-ar and young exposure dates for the windjana sandstone, kimberley, gale crater, mars |
publisher |
American Geophysical Union |
publishDate |
2016 |
url |
https://authors.library.caltech.edu/71199/ https://authors.library.caltech.edu/71199/2/Vasconcelos_et_al-2016-Journal_of_Geophysical_Research__Planets.pdf https://authors.library.caltech.edu/71199/1/jgre20600.pdf https://resolver.caltech.edu/CaltechAUTHORS:20161018-073743780 |
long_lat |
ENVELOPE(-114.336,-114.336,62.367,62.367) |
geographic |
Yellowknife Yellowknife Bay |
geographic_facet |
Yellowknife Yellowknife Bay |
genre |
Yellowknife |
genre_facet |
Yellowknife |
op_relation |
https://authors.library.caltech.edu/71199/2/Vasconcelos_et_al-2016-Journal_of_Geophysical_Research__Planets.pdf https://authors.library.caltech.edu/71199/1/jgre20600.pdf Vasconcelos, P. M. and Farley, K. A. and Malespin, C. A. and Mahaffy, P. and Ming, D. and McLennan, S. M. and Hurowitz, J. A. and Rice, Melissa S. (2016) Discordant K-Ar and Young Exposure Dates for the Windjana sandstone, Kimberley, Gale Crater, Mars. Journal of Geophysical Research. Planets, 121 (10). pp. 2176-2192. ISSN 2169-9097. doi:10.1002/2016JE005017. https://resolver.caltech.edu/CaltechAUTHORS:20161018-073743780 <https://resolver.caltech.edu/CaltechAUTHORS:20161018-073743780> |
op_rights |
other |
op_doi |
https://doi.org/10.1002/2016JE005017 |
container_title |
Journal of Geophysical Research: Planets |
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121 |
container_issue |
10 |
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2176 |
op_container_end_page |
2192 |
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1766236859555381248 |