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Orbital evidence for more widespread carbonate-bearing rocks on Mars

Wray, James J. and Murchie, Scott L. and Bishop, Janice L. and Ehlmann, Bethany L. and Milliken, Ralph E. and Wilhelm, Mary Beth and Seelos, Kimberly D. and Chojnacki, Matthew (2016) Orbital evidence for more widespread carbonate-bearing rocks on Mars. Journal of Geophysical Research. Planets, 121 (4). pp. 652-677. ISSN 2169-9097.

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Carbonates are key minerals for understanding ancient Martian environments because they are indicators of potentially habitable, neutral-to-alkaline water and may be an important reservoir for paleoatmospheric CO_2. Previous remote sensing studies have identified mostly Mg-rich carbonates, both in Martian dust and in a Late Noachian rock unit circumferential to the Isidis basin. Here we report evidence for older Fe- and/or Ca-rich carbonates exposed from the subsurface by impact craters and troughs. These carbonates are found in and around the Huygens basin northwest of Hellas, in western Noachis Terra between the Argyre basin and Valles Marineris, and in other isolated locations spread widely across the planet. In all cases they cooccur with or near phyllosilicates, and in Huygens basin specifically they occupy layered rocks exhumed from up to ~5 km depth. We discuss factors that might explain their observed regional distribution, arguments for why carbonates may be even more widespread in Noachian materials than presently appreciated and what could be gained by targeting these carbonates for further study with future orbital or landed missions to Mars.

Item Type:Article
Related URLs:
URLURL TypeDescription
http://uahirise.orgRelated ItemHiRISE images
http://crism-map.jhuapl.eduRelated ItemCRISM images
Murchie, Scott L.0000-0002-1616-8751
Ehlmann, Bethany L.0000-0002-2745-3240
Milliken, Ralph E.0000-0003-3240-4918
Additional Information:© 2016 American Geophysical Union. Received 9 NOV 2015; Accepted 3 APR 2016; Accepted article online 7 APR 2016; Published online 22 APR 2016. We thank the Mars Reconnaissance Orbiter HiRISE and CRISM instrument teams for acquiring critical data and for their financial, scientific, and collegial support. All HiRISE images used herein are publicly available at and all CRISM images at All other Mars data sets are accessible via the Google Mars interface. Fe-oxalate mineral spectra and CRISM regions of interest are available from the corresponding author upon request. J.J.W.'s work on this project was supported in part by the NASA Astrobiology Institute's SETI Institute node (grant 15BB01). Scientific discussions with Sheridan Ackiss, Veronica Bray, Debra Buczkowski, Roger Clark, Dick Morris, Eldar Noe Dobrea, Gregg Swayze, and Christina Viviano-Beck improved the paper. We thank Paul Niles and an anonymous reviewer for their detailed technical feedback, which strengthened the paper.
Funding AgencyGrant Number
Subject Keywords:Mars; carbonate; spectroscopy; Noachian; CRISM; HiRISE
Issue or Number:4
Record Number:CaltechAUTHORS:20160811-081402790
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Official Citation:Wray, J. J., S. L. Murchie, J. L. Bishop, B. L. Ehlmann, R. E. Milliken, M. B. Wilhelm, K. D. Seelos, and M. Chojnacki (2016), Orbital evidence for more widespread carbonate-bearing rocks on Mars, J. Geophys. Res. Planets, 121, 652–677, doi:10.1002/2015JE004972
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:69562
Deposited By: Tony Diaz
Deposited On:11 Aug 2016 17:03
Last Modified:09 Mar 2020 13:19

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