CaltechAUTHORS
  A Caltech Library Service

Mineralogy and stratigraphy of the Gale crater rim, wall, and floor units

Buz, Jennifer and Ehlmann, Bethany L. and Pan, Lu and Grotzinger, John P. (2017) Mineralogy and stratigraphy of the Gale crater rim, wall, and floor units. Journal of Geophysical Research. Planets, 122 (5). pp. 1090-1118. ISSN 2169-9097. https://resolver.caltech.edu/CaltechAUTHORS:20170619-074409915

[img] PDF - Published Version
Creative Commons Attribution Non-commercial No Derivatives.

3510Kb

Use this Persistent URL to link to this item: https://resolver.caltech.edu/CaltechAUTHORS:20170619-074409915

Abstract

The Curiosity rover has detected diverse lithologies in float rocks and sedimentary units on the Gale crater floor, interpreted to have been transported from the rim. To understand their provenance, we examine the mineralogy and geology of Gale's rim, walls, and floor, using high-resolution imagery and infrared spectra. While no significant differences in bedrock spectral properties were observed within most Thermal Emission Imaging System and Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) scenes, some CRISM scenes of rim and wall rocks showed olivine-bearing bedrock accompanied by Fe/Mg phyllosilicates. Hydrated materials with 2.48 μm absorptions in Gale's eastern walls are spectrally similar to the sulfate unit in Mount Sharp (Aeolis Mons). Sedimentary strata on the Gale floor southwest of the landing site, likely coeval with the Bradbury units explored by Curiosity, also are hydrated and/or have Fe/Mg phyllosilicates. Spectral properties of these phyllosilicates differ from the Al-substituted nontronite detected by CRISM in Mount Sharp, suggesting formation by fluids of different composition. Geologic mapping of the crater floor shows that the hydrated or hydroxylated materials are typically overlain by spectrally undistinctive, erosionally resistant, cliff-forming units. Additionally, a 4 km impact crater exposes >250 m of the Gale floor, including finely layered units. No basement rocks are exposed, thus indicating sedimentary deposits ≥250 m beneath strata studied by Curiosity. Collectively, the data indicate substantial sedimentary infill of Gale crater, including some materials derived from the crater rim. Lowermost thin layers are consistent with deposition in a lacustrine environment; interbedded hydrated/hydroxylated units may signify changing environmental conditions, perhaps in a drying or episodically dry lake bed.


Item Type:Article
Related URLs:
URLURL TypeDescription
http://dx.doi.org/10.1002/2016JE005163DOIArticle
http://onlinelibrary.wiley.com/doi/10.1002/2016JE005163/abstractPublisherArticle
ORCID:
AuthorORCID
Buz, Jennifer0000-0002-0491-2686
Ehlmann, Bethany L.0000-0002-2745-3240
Pan, Lu0000-0002-8151-2125
Grotzinger, John P.0000-0001-9324-1257
Additional Information:© 2017 The Authors. This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made. Received 1 SEP 2016; Accepted 17 APR 2017; Accepted article online 20 APR 2017; Published online 30 MAY 2017. All data used in this paper are available in the NASA Planetary Data System; derived products are available by request. Thanks to efforts of the many spacecraft and instrument teams for their collection of these right data sets. Thanks to Ara Oshagan, Christopher Edwards, and Daven Quinn for assistance with data processing. J.B. was supported by a NASA Earth and Space Sciences Fellowship NNX15AQ95H for the conduct of this work. Partial support was also provided by an MSL Participating Scientist grant to B.L.E. We also thank Sanjeev Gupta and an anonymous reviewer for their comments and suggestions, which have improved this manuscript.
Group:Astronomy Department
Funders:
Funding AgencyGrant Number
NASANNX15AQ95H
Mars Science Laboratory (MSL)UNSPECIFIED
Subject Keywords:planetary geology; remote sensing; mineralogy
Issue or Number:5
Record Number:CaltechAUTHORS:20170619-074409915
Persistent URL:https://resolver.caltech.edu/CaltechAUTHORS:20170619-074409915
Official Citation:Buz, J., B. L. Ehlmann, L. Pan, and J. P. Grotzinger (2017), Mineralogy and stratigraphy of the Gale crater rim, wall, and floor units, J. Geophys. Res. Planets, 122, 1090–1118, doi:10.1002/2016JE005163
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:78316
Collection:CaltechAUTHORS
Deposited By: Tony Diaz
Deposited On:27 Jun 2017 20:18
Last Modified:20 Apr 2020 08:47

Repository Staff Only: item control page