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Identification and Description of a Silicic Volcaniclastic Layer in Gale Crater, Mars, Using Active Neutron Interrogation

Czarnecki, S. and Hardgrove, C. and Gasda, P. J. and Gabriel, T. S. J. and Starr, M. and Rice, M. S. and Frydenvang, J. and Wiens, R. C. and Rapin, W. and Nikiforov, S. and Lisov, D. and Litvak, M. and Calef, F. and Gengl, H. and Newsom, H. and Thompson, L. and Nowicki, S. (2020) Identification and Description of a Silicic Volcaniclastic Layer in Gale Crater, Mars, Using Active Neutron Interrogation. Journal of Geophysical Research. Planets, 125 (3). Art. No. e2019JE006180. ISSN 2169-9097.

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The Dynamic Albedo of Neutrons instrument aboard the Mars Science Laboratory rover, Curiosity, has been used to map a stratigraphically conformable layer of high‐SiO² material in Gale crater. Previous work has shown that this material contains tridymite, a high‐temperature/low‐pressure felsic mineral, interpreted to have a volcanic source rock. We describe several characteristics including orientation, extent, hydration, and geochemistry, consistent with a volcaniclastic material conformably deposited within a lacustrine mudstone succession. Relationships with widely dispersed alteration features and orbital detections of hydrated SiO² suggest that this high‐SiO² layer extends at least 17 km laterally. Mineralogical abundances previously reported for this high‐SiO² material indicated that hydrous species were restricted to the amorphous (non‐crystalline) fraction, which is dominated by SiO². The low mean bulk hydration of this high‐SiO² layer (1.85 ± 0.13 wt.% water‐equivalent hydrogen) is consistent with silicic glass in addition to opal‐A and opal‐CT. Persistent volcanic glass and tridymite in addition to opal in an ancient sedimentary unit indicates that the conversion to more ordered forms of crystalline SiO² has not proceeded to completion and that this material has had only limited exposure to water since it originally erupted, despite having been transported in a fluviolacustrine system. Our results, including the conformable nature, large areal extent, and presence of volcanic glass, indicate that this high‐SiO² material is derived from the product of evolved magma on Mars. This is the first identification of a silicic volcaniclastic layer on another planet and has important implications for magma evolution mechanisms on single‐plate planets.

Item Type:Article
Related URLs:
URLURL TypeDescription
Czarnecki, S.0000-0002-4300-4066
Hardgrove, C.0000-0002-8556-6630
Gasda, P. J.0000-0003-0895-1153
Gabriel, T. S. J.0000-0002-9767-4153
Rice, M. S.0000-0002-8370-4139
Frydenvang, J.0000-0001-9294-1227
Wiens, R. C.0000-0002-3409-7344
Rapin, W.0000-0003-4660-8006
Nikiforov, S.0000-0002-7221-8602
Lisov, D.0000-0002-3306-9819
Calef, F.0000-0002-5132-3980
Newsom, H.0000-0002-4358-8161
Thompson, L.0000-0002-5444-952X
Nowicki, S.0000-0003-1140-6703
Additional Information:© 2020 The Authors. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited. Received 22 AUG 2019; Accepted 12 JAN 2020; Accepted article online 30 JAN 2020. The authors are grateful to JPL for developing and operating the MSL Curiosity rover mission and to the Mars Science Laboratory team for facilitating the multinational collaboration involving scientists from the United States, Denmark, France, Russia, and Canada to synthesize results from several MSL instrument data sets to make this work possible. We also would like to individually thank Marion Nachon, Abigail Fraeman, and Vivian Sun for helpful conversations regarding aspects of this work. This work was supported by the Mars Science Laboratory Participating Scientist Program, the Los Alamos National Laboratory Center for the Study of Earth and Space, the NASA Earth and Space Exploration Fellowship, the Elwha Stipend of Western Washington University, and the Carlsberg Foundation. The authors acknowledge Research Computing at Arizona State University for providing HPC, storage, etc., resources that have contributed to the research results reported within this paper (URL: All data used for this work are available on the NASA Planetary Data System via links on the MSL page (URL:
Funding AgencyGrant Number
Los Alamos National LaboratoryUNSPECIFIED
NASA Earth and Space Science FellowshipUNSPECIFIED
Western Washington UniversityUNSPECIFIED
Carlsberg FoundationUNSPECIFIED
Subject Keywords:Gale crater; neutron spectroscopy; Marias Pass; evolved igneous lithology; Mars water; silica
Issue or Number:3
Record Number:CaltechAUTHORS:20200409-094128656
Persistent URL:
Official Citation:Czarnecki, S., Hardgrove, C., Gasda, P. J., Gabriel, T. S. J., Starr, M., Rice, M. S., et al. (2020). Identification and description of a silicic volcaniclastic layer in Gale crater, Mars, using active neutron interrogation. Journal of Geophysical Research: Planets, 125, e2019JE006180.
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:102429
Deposited By: Tony Diaz
Deposited On:09 Apr 2020 16:56
Last Modified:09 Apr 2020 16:56

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