{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,21]],"date-time":"2026-07-21T20:03:34Z","timestamp":1784664214755,"version":"3.55.0"},"reference-count":51,"publisher":"National Academy of Sciences","issue":"25","license":[{"start":{"date-parts":[[2025,6,16]],"date-time":"2025-06-16T00:00:00Z","timestamp":1750032000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by-nc-nd\/4.0\/"}],"funder":[{"DOI":"10.13039\/100008634","name":"University of Texas at San Antonio","doi-asserted-by":"publisher","award":["N\/A"],"award-info":[{"award-number":["N\/A"]}],"id":[{"id":"10.13039\/100008634","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/100000104","name":"National Aeronautics and Space Administration","doi-asserted-by":"publisher","award":["80GSFC24M0006"],"award-info":[{"award-number":["80GSFC24M0006"]}],"id":[{"id":"10.13039\/100000104","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":["www.pnas.org"],"crossmark-restriction":true},"short-container-title":["Proc. Natl. Acad. Sci. U.S.A."],"published-print":{"date-parts":[[2025,6,24]]},"abstract":"<jats:p>\n                    Pure siderite [Fe\n                    <jats:sup>II<\/jats:sup>\n                    CO\n                    <jats:sub>3<\/jats:sub>\n                    ] was recently discovered in abundant quantities (4.8 to 10.5 wt.%) by the Curiosity rover at Gale crater, Mars. Diagenetic alteration of siderite likely caused the carbonate-sequestered CO\n                    <jats:sub>2<\/jats:sub>\n                    to be released back into the atmosphere and consequently produced ferric [Fe(III)] oxyhydr(oxide) minerals. Here, using laboratory experimentation, we demonstrate that while closed system acid diagenesis\u2014as proposed for Gale crater\u2014is incapable of effective siderite alteration in Mars-relevant fluids, oxyhalogen compounds (chlorate and bromate) can weather siderite not only at acidic pH but also in near-neutral Mars-relevant solutions. The ferric oxyhydroxide minerals produced as a consequence are controlled by the diagenetic fluid composition. While photooxidation is possible, the mutually exclusive products of alteration\u2014magnetite (Fe\n                    <jats:sub>3<\/jats:sub>\n                    O\n                    <jats:sub>4<\/jats:sub>\n                    ) during ultraviolet irradiation and ferric oxyhydroxide (FeOOH) by oxyhalogens\u2014demonstrate that siderite at Gale crater underwent chemical weathering by chlorate and bromate brines owing to the complete absence of magnetite in drill samples containing siderite. We propose a top\u2013down oxyhalogen brine percolation model to explain the iron mineralogy of the sulfate-rich unit at Gale crater. We conclude that siderite alteration by acidic fluids alone cannot explain the redox disequilibrium witnessed in Gale crater sediments as promulgated before and siderite weathering by oxyhalogen brines is the most likely explanation. It is highly likely that the halogen cycle on Mars is interlinked to the iron and the carbon cycle on early and current Mars.\n                  <\/jats:p>","DOI":"10.1073\/pnas.2504674122","type":"journal-article","created":{"date-parts":[[2025,6,16]],"date-time":"2025-06-16T15:50:21Z","timestamp":1750089021000},"update-policy":"https:\/\/doi.org\/10.1073\/pnas.cm10313","source":"Crossref","is-referenced-by-count":3,"title":["Siderite and ferric oxyhydroxides imply interlinked carbon, iron, and halogen cycles on Mars"],"prefix":"10.1073","volume":"122","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-9673-1032","authenticated-orcid":false,"given":"Kaushik","family":"Mitra","sequence":"first","affiliation":[{"name":"Department of Earth & Planetary Sciences, The University of Texas at San Antonio","place":["San Antonio"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Lauren A.","family":"Malesky","sequence":"additional","affiliation":[{"name":"Department of Earth & Planetary Sciences, The University of Texas at San Antonio","place":["San Antonio"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1235-9016","authenticated-orcid":false,"given":"Michael T.","family":"Thorpe","sequence":"additional","affiliation":[{"name":"University of Maryland\/NASA Goddard Space Flight Center\/ Center for Research and Exploration in Space and Science Technology (CRESST II)","place":["Greenbelt"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ana","family":"Stevanovic","sequence":"additional","affiliation":[{"name":"Kleberg Advanced Microscopy Center, The University of Texas at San Antonio","place":["San Antonio"]}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"341","published-online":{"date-parts":[[2025,6,16]]},"reference":[{"key":"e_1_3_4_1_2","doi-asserted-by":"publisher","DOI":"10.1029\/JS082i028p04559"},{"key":"e_1_3_4_2_2","doi-asserted-by":"publisher","DOI":"10.1038\/s41561-021-00701-8"},{"key":"e_1_3_4_3_2","doi-asserted-by":"publisher","DOI":"10.1007\/s11214-012-9940-y"},{"key":"e_1_3_4_4_2","first-page":"89","volume-title":"Carbonates on Mars in Volatiles in the Martian Crust","author":"Bridges J. C.","year":"2019","unstructured":"J. C. Bridges, L. J. Hicks, A. H. Treiman, Carbonates on Mars in Volatiles in the Martian Crust (Elsevier, 2019), pp. 89\u2013118."},{"key":"e_1_3_4_5_2","doi-asserted-by":"publisher","DOI":"10.1029\/1998JE001020"},{"key":"e_1_3_4_6_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.epsl.2005.10.021"},{"key":"e_1_3_4_7_2","doi-asserted-by":"publisher","DOI":"10.1038\/nature02911"},{"key":"e_1_3_4_8_2","doi-asserted-by":"publisher","DOI":"10.1126\/science.1122659"},{"key":"e_1_3_4_9_2","first-page":"1564","article-title":"In situ evidence of an active carbon cycle on ancient Mars","volume":"3040","author":"Tutolo B.","year":"2025","unstructured":"B. Tutolo , In situ evidence of an active carbon cycle on ancient Mars. Science 3040, 1564 (2025).","journal-title":"Science"},{"key":"e_1_3_4_10_2","doi-asserted-by":"publisher","DOI":"10.1029\/2021JE007099"},{"key":"e_1_3_4_11_2","doi-asserted-by":"publisher","DOI":"10.1038\/s41550-019-0990-x"},{"key":"e_1_3_4_12_2","doi-asserted-by":"publisher","DOI":"10.1073\/pnas.2321342121"},{"key":"e_1_3_4_13_2","doi-asserted-by":"publisher","DOI":"10.2138\/am.2013.4187"},{"key":"e_1_3_4_14_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.chemgeo.2022.121146"},{"key":"e_1_3_4_15_2","doi-asserted-by":"publisher","DOI":"10.1126\/sciadv.aau0872"},{"key":"e_1_3_4_16_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.gca.2022.02.003"},{"key":"e_1_3_4_17_2","doi-asserted-by":"publisher","DOI":"10.3847\/PSJ\/ac13a3"},{"key":"e_1_3_4_18_2","doi-asserted-by":"publisher","DOI":"10.1073\/pnas.1308958110"},{"key":"e_1_3_4_19_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.epsl.2017.04.021"},{"key":"e_1_3_4_20_2","doi-asserted-by":"publisher","DOI":"10.1002\/2015GL064290"},{"key":"e_1_3_4_21_2","doi-asserted-by":"publisher","DOI":"10.1038\/s41550-021-01588-6"},{"key":"e_1_3_4_22_2","doi-asserted-by":"publisher","DOI":"10.1017\/S1473550416000057"},{"key":"e_1_3_4_23_2","doi-asserted-by":"publisher","DOI":"10.1029\/2019JE006133"},{"key":"e_1_3_4_24_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.epsl.2023.118464"},{"key":"e_1_3_4_25_2","doi-asserted-by":"publisher","DOI":"10.3390\/min10090729"},{"key":"e_1_3_4_26_2","doi-asserted-by":"publisher","DOI":"10.1021\/acsearthspacechem.1c00379"},{"key":"e_1_3_4_27_2","doi-asserted-by":"publisher","DOI":"10.1038\/s41561-022-01094-y"},{"key":"e_1_3_4_28_2","doi-asserted-by":"publisher","DOI":"10.1002\/j.1551-8833.1994.tb06263.x"},{"key":"e_1_3_4_29_2","doi-asserted-by":"publisher","DOI":"10.1029\/2024GL111114"},{"key":"e_1_3_4_30_2","doi-asserted-by":"publisher","DOI":"10.1017\/S1473550415000385"},{"key":"e_1_3_4_31_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.epsl.2015.09.003"},{"key":"e_1_3_4_32_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.icarus.2013.11.012"},{"key":"e_1_3_4_33_2","doi-asserted-by":"publisher","DOI":"10.1126\/science.1172466"},{"key":"e_1_3_4_34_2","doi-asserted-by":"publisher","DOI":"10.1029\/2012GL051239"},{"key":"e_1_3_4_35_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.epsl.2015.12.013"},{"key":"e_1_3_4_36_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.epsl.2016.10.028"},{"key":"e_1_3_4_37_2","doi-asserted-by":"publisher","DOI":"10.1089\/ast.2013.0999"},{"key":"e_1_3_4_38_2","doi-asserted-by":"publisher","DOI":"10.1002\/2016GL072199"},{"key":"e_1_3_4_39_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.epsl.2018.06.011"},{"key":"e_1_3_4_40_2","first-page":"367","article-title":"Mars, a volatile-rich planet","volume":"20","author":"Dreibus G.","year":"1985","unstructured":"G. Dreibus, H. Wanke, Mars, a volatile-rich planet. Meteoritics 20, 367\u2013381 (1985).","journal-title":"Meteoritics"},{"key":"e_1_3_4_41_2","doi-asserted-by":"publisher","DOI":"10.1007\/978-3-319-61667-4_16"},{"key":"e_1_3_4_42_2","doi-asserted-by":"publisher","DOI":"10.1029\/2020JE006536"},{"key":"e_1_3_4_43_2","doi-asserted-by":"publisher","DOI":"10.1002\/2017JE005474"},{"key":"e_1_3_4_44_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.actaastro.2019.08.026"},{"key":"e_1_3_4_45_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.epsl.2018.06.015"},{"key":"e_1_3_4_46_2","doi-asserted-by":"publisher","DOI":"10.1002\/3527602097"},{"key":"e_1_3_4_47_2","doi-asserted-by":"publisher","DOI":"10.1029\/2023JE008041"},{"key":"e_1_3_4_48_2","doi-asserted-by":"publisher","DOI":"10.1029\/2024GL111113"},{"key":"e_1_3_4_49_2","doi-asserted-by":"publisher","DOI":"10.1038\/s41561-019-0458-8"},{"key":"e_1_3_4_50_2","doi-asserted-by":"publisher","DOI":"10.1089\/ast.2015.1432"},{"key":"e_1_3_4_51_2","unstructured":"K. Mitra Data from \u201cSiderite and Ferric Oxyhydroxides Imply Interlinked Carbon Iron & Halogen Cycles on Mars.\u201d Figshare. https:\/\/figshare.com\/articles\/dataset\/dx_doi_org_10_6084_m9_figshare_27225450\/27225450. Deposited 27 February 2025."}],"container-title":["Proceedings of the National Academy of Sciences"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/pnas.org\/doi\/pdf\/10.1073\/pnas.2504674122","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,6,16]],"date-time":"2025-06-16T15:50:55Z","timestamp":1750089055000},"score":1,"resource":{"primary":{"URL":"https:\/\/pnas.org\/doi\/10.1073\/pnas.2504674122"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2025,6,16]]},"references-count":51,"journal-issue":{"issue":"25","published-print":{"date-parts":[[2025,6,24]]}},"alternative-id":["10.1073\/pnas.2504674122"],"URL":"https:\/\/doi.org\/10.1073\/pnas.2504674122","relation":{},"ISSN":["0027-8424","1091-6490"],"issn-type":[{"value":"0027-8424","type":"print"},{"value":"1091-6490","type":"electronic"}],"subject":[],"published":{"date-parts":[[2025,6,16]]},"assertion":[{"value":"2025-02-27","order":0,"name":"received","label":"Received","group":{"name":"publication_history","label":"Publication History"}},{"value":"2025-04-21","order":2,"name":"accepted","label":"Accepted","group":{"name":"publication_history","label":"Publication History"}},{"value":"2025-06-16","order":3,"name":"published","label":"Published","group":{"name":"publication_history","label":"Publication History"}}],"article-number":"e2504674122"}}