Version 2 2025-05-07, 14:42Version 2 2025-05-07, 14:42
Version 1 2025-05-07, 14:14Version 1 2025-05-07, 14:14
journal contribution
posted on 2025-05-07, 14:42authored byBenjamin M Tutolo, Elisabeth M Hausrath, Edwin S Kite, Elizabeth B Rampe, Thomas F Bristow, Robert T Downs, Allan Treiman, Tanya S Peretyazhko, Michael T Thorpe, John P Grotzinger, Amelie L Roberts, P Douglas Archer, David J Des Marais, David F Blake, David T Vaniman, Shaunna M Morrison, Steve Chipera, Robert M Hazen, Richard V Morris, Valerie M Tu, Sarah L Simpson, Aditi Pandey, Albert Yen, Stephen R Larter, Patricia Craig, Nicholas Castle, Douglas W Ming, Johannes M Meusburger, Abigail A Fraeman, David G Burtt, Heather B Franz, Brad Sutter, Joanna V Clark, William Rapin, John BridgesJohn Bridges, Matteo Loche, Patrick Gasda, Jens Frydenvang, Ashwin R Vasavada
Ancient Mars had surface liquid water and a dense carbon dioxide (CO
2
)–rich atmosphere. Such an atmosphere would interact with crustal rocks, potentially leaving a mineralogical record of its presence. We analyzed the composition of an 89-meter stratigraphic section of Gale crater, Mars, using data collected by the Curiosity rover. An iron carbonate mineral, siderite, occurs in abundances of 4.8 to 10.5 weight %, colocated with highly water-soluble salts. We infer that the siderite formed in water-limited conditions, driven by water-rock reactions and evaporation. Comparison with orbital data indicates that similar strata (deposited globally) sequestered the equivalent of 2.6 to 36 millibar of atmospheric CO
2
. The presence of iron oxyhydroxides in these deposits indicates that a partially closed carbon cycle on ancient Mars returned some previously sequestered CO
2
to the atmosphere.
History
Author affiliation
College of Science & Engineering
Physics & Astronomy
Version
AM (Accepted Manuscript)
Published in
Science
Volume
388
Issue
6744
Pagination
292 - 297
Publisher
American Association for the Advancement of Science (AAAS)