Mineralogy and chemistry of altered Icelandic basalts: Application to clay mineral detection and understanding aqueous environments on Mars
We used a suite of techniques, including those emulating compositional data sets obtained from Mars orbit and obtainable at the Mars surface, to examine aqueous alteration of basaltic rocks from Iceland as a mineralogic and geochemical analog for Noachian environments on Mars. A sample suite was col...
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ftcaltechauth:oai:authors.library.caltech.edu:z2xp0-78545 2024-10-13T14:08:32+00:00 Mineralogy and chemistry of altered Icelandic basalts: Application to clay mineral detection and understanding aqueous environments on Mars Ehlmann, B. L. Bish, D. L. Ruff, S. W. Mustard, J. F. 2012-10-13 https://doi.org/10.1029/2012JE004156 unknown American Geophysical Union https://doi.org/10.1029/2012JE004156 eprintid:43941 info:eu-repo/semantics/openAccess Other Journal of Geophysical Research E, 117(E11), Art. No. E00J16, (2012-10-13) XRD clay minerals hydrothermal alteration infrared spectroscopy weathering zeolites info:eu-repo/semantics/article 2012 ftcaltechauth https://doi.org/10.1029/2012JE004156 2024-09-25T18:46:45Z We used a suite of techniques, including those emulating compositional data sets obtained from Mars orbit and obtainable at the Mars surface, to examine aqueous alteration of basaltic rocks from Iceland as a mineralogic and geochemical analog for Noachian environments on Mars. A sample suite was collected for laboratory measurement of (1) whole-rock visible/near-infrared (VNIR) reflectance and thermal infrared (TIR) emission spectra; (2) VNIR and TIR reflectance spectra of particle-size separates derived from the bulk rock and from materials extracted from fractures/vesicles; (3) X-ray diffraction (XRD) patterns for determination of quantitative modal mineralogy; (4) major element chemistry using flux fusion of whole-rock powders; and (5) electron microprobe analyses of minerals in thin sections. Conclusions about aqueous alteration can be influenced by technique. For these basalts, whole-rock chemical data showed scant evidence for chemical fractionation, but TIR, VNIR, and XRD measurements identified distinctive assemblages of hydrous silicate minerals, differing by sample. XRD provided the most complete and accurate quantitative determination of sample mineralogy. However, VNIR spectroscopy was the technique most useful for determining composition of low-abundance smectite clays, and TIR spectroscopy was the most useful for recognizing hydrated silicates in thin surface coatings. High spatial resolution mineralogical and chemical data sets were useful for understanding the texture and distribution of alteration products and variations in fluid chemistry. No single approach provides a complete assessment of the environment of alteration, demonstrating the importance of employing multiple, synergistic mineralogical and geochemical techniques and instruments in exploration of rock strata from aqueous paleoenvironments on Mars. © 2012 American Geophysical Union. Received 6 June 2012; revised 16 August 2012; accepted 20 August 2012; published 13 October 2012. This work benefited from the invaluable advice and ... Article in Journal/Newspaper Iceland Caltech Authors (California Institute of Technology) Journal of Geophysical Research: Planets 117 E11 |
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Open Polar |
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Caltech Authors (California Institute of Technology) |
op_collection_id |
ftcaltechauth |
language |
unknown |
topic |
XRD clay minerals hydrothermal alteration infrared spectroscopy weathering zeolites |
spellingShingle |
XRD clay minerals hydrothermal alteration infrared spectroscopy weathering zeolites Ehlmann, B. L. Bish, D. L. Ruff, S. W. Mustard, J. F. Mineralogy and chemistry of altered Icelandic basalts: Application to clay mineral detection and understanding aqueous environments on Mars |
topic_facet |
XRD clay minerals hydrothermal alteration infrared spectroscopy weathering zeolites |
description |
We used a suite of techniques, including those emulating compositional data sets obtained from Mars orbit and obtainable at the Mars surface, to examine aqueous alteration of basaltic rocks from Iceland as a mineralogic and geochemical analog for Noachian environments on Mars. A sample suite was collected for laboratory measurement of (1) whole-rock visible/near-infrared (VNIR) reflectance and thermal infrared (TIR) emission spectra; (2) VNIR and TIR reflectance spectra of particle-size separates derived from the bulk rock and from materials extracted from fractures/vesicles; (3) X-ray diffraction (XRD) patterns for determination of quantitative modal mineralogy; (4) major element chemistry using flux fusion of whole-rock powders; and (5) electron microprobe analyses of minerals in thin sections. Conclusions about aqueous alteration can be influenced by technique. For these basalts, whole-rock chemical data showed scant evidence for chemical fractionation, but TIR, VNIR, and XRD measurements identified distinctive assemblages of hydrous silicate minerals, differing by sample. XRD provided the most complete and accurate quantitative determination of sample mineralogy. However, VNIR spectroscopy was the technique most useful for determining composition of low-abundance smectite clays, and TIR spectroscopy was the most useful for recognizing hydrated silicates in thin surface coatings. High spatial resolution mineralogical and chemical data sets were useful for understanding the texture and distribution of alteration products and variations in fluid chemistry. No single approach provides a complete assessment of the environment of alteration, demonstrating the importance of employing multiple, synergistic mineralogical and geochemical techniques and instruments in exploration of rock strata from aqueous paleoenvironments on Mars. © 2012 American Geophysical Union. Received 6 June 2012; revised 16 August 2012; accepted 20 August 2012; published 13 October 2012. This work benefited from the invaluable advice and ... |
format |
Article in Journal/Newspaper |
author |
Ehlmann, B. L. Bish, D. L. Ruff, S. W. Mustard, J. F. |
author_facet |
Ehlmann, B. L. Bish, D. L. Ruff, S. W. Mustard, J. F. |
author_sort |
Ehlmann, B. L. |
title |
Mineralogy and chemistry of altered Icelandic basalts: Application to clay mineral detection and understanding aqueous environments on Mars |
title_short |
Mineralogy and chemistry of altered Icelandic basalts: Application to clay mineral detection and understanding aqueous environments on Mars |
title_full |
Mineralogy and chemistry of altered Icelandic basalts: Application to clay mineral detection and understanding aqueous environments on Mars |
title_fullStr |
Mineralogy and chemistry of altered Icelandic basalts: Application to clay mineral detection and understanding aqueous environments on Mars |
title_full_unstemmed |
Mineralogy and chemistry of altered Icelandic basalts: Application to clay mineral detection and understanding aqueous environments on Mars |
title_sort |
mineralogy and chemistry of altered icelandic basalts: application to clay mineral detection and understanding aqueous environments on mars |
publisher |
American Geophysical Union |
publishDate |
2012 |
url |
https://doi.org/10.1029/2012JE004156 |
genre |
Iceland |
genre_facet |
Iceland |
op_source |
Journal of Geophysical Research E, 117(E11), Art. No. E00J16, (2012-10-13) |
op_relation |
https://doi.org/10.1029/2012JE004156 eprintid:43941 |
op_rights |
info:eu-repo/semantics/openAccess Other |
op_doi |
https://doi.org/10.1029/2012JE004156 |
container_title |
Journal of Geophysical Research: Planets |
container_volume |
117 |
container_issue |
E11 |
_version_ |
1812815212576768000 |