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Hydrated silica on Mars: Combined analysis with near-infrared and thermal-infrared spectroscopy

Smith, Matthew R. and Bandfield, Joshua L. and Cloutis, Edward A. and Rice, Melissa S. (2013) Hydrated silica on Mars: Combined analysis with near-infrared and thermal-infrared spectroscopy. Icarus, 223 (2). pp. 633-648. ISSN 0019-1035. doi:10.1016/j.icarus.2013.01.024.

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Hydrated silica is found in a variety of martian deposits within aqueously altered mineral suites. Its common occurrence is attributed to its ease of formation in different weathering environments. Because of its presence in disparate units, hydrated silica makes a good tracer mineral to compare otherwise dissimilar martian deposits and relate their relative degrees of aqueous alteration. This work combines near-infrared and thermal-infrared spectroscopy to determine the relative degree of crystallinity and bulk SiO_2 abundance of surfaces containing hydrated silica. A range of crystalline structures are present, from non-crystalline (hydrated glass) to weakly crystalline (opal) to crystalline (quartz), implying a range in the maturity of these silica deposits. However, bulk SiO_2 contents show less diversity, with most martian hydrated silica deposits having SiO_2 abundances similar to Surface Type 2 (basaltic andesite or weathered basaltic composition)—a widespread and common surface composition that suggests limited interaction with water. We also find that hydrated silica crystallinity—as a proxy for degree of alteration—is correlated with the geochemistry of the deposit as inferred by its associated minerals: highly crystalline hydrated silica is found with Fe/Mg-phyllosilicates, moderately crystalline hydrated silica is associated with Al-phyllosilicates, and poorly crystalline phases are associated with sulfates. This corroborates previous predictions of the waning of surficial water from the Noachian → Hesperian and demonstrates the usefulness of hydrated silica as a stand-alone mineral for predicting the degree of alteration of ancient mineral suites.

Item Type:Article
Related URLs:
URLURL TypeDescription
Cloutis, Edward A.0000-0001-7301-0929
Rice, Melissa S.0000-0002-8370-4139
Additional Information:© 2013 Elsevier Inc. Received 17 October 2012. Revised 26 January 2013. Accepted 27 January 2013. Available online 8 February 2013. Funding for this Project was partially provided by Grants from the NASA Mars Data Analysis Program (NNX10AQ33G) and the JPL Critical Data Products initiative for characterization of potential future landing sites. We thank Alan Gillespie, Dave Montgomery, Steve Wood, and Qiang Fu for their many helpful comments. We also thank the TES, THEMIS, MOLA, CTX, CRISM, and HiRISE science and operations teams for the production of high quality datasets. Data analysis was facilitated through the use of JMARS developed at ASU. E.A.C. thanks NSERC and the Canadian Space Agency for support of this study.
Funding AgencyGrant Number
NASA Mars Data Analysis ProgramNNX10AQ33G
JPL Critical Data Products initiativeUNSPECIFIED
Natural Sciences and Engineering Research Council of Canada (NSERC)UNSPECIFIED
Canadian Space AgencyUNSPECIFIED
Subject Keywords:Mars, Surface; Spectroscopy; Mineralogy; Geological processes
Issue or Number:2
Record Number:CaltechAUTHORS:20130510-083118036
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Official Citation:Matthew R. Smith, Joshua L. Bandfield, Edward A. Cloutis, Melissa S. Rice, Hydrated silica on Mars: Combined analysis with near-infrared and thermal-infrared spectroscopy, Icarus, Volume 223, Issue 2, April 2013, Pages 633-648, ISSN 0019-1035, 10.1016/j.icarus.2013.01.024. (
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:38410
Deposited By: Ruth Sustaita
Deposited On:10 May 2013 15:57
Last Modified:09 Nov 2021 23:37

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