{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,14]],"date-time":"2026-10-14T05:47:42Z","timestamp":1791956862156,"version":"4.3.4"},"reference-count":90,"publisher":"SAGE Publications","issue":"10","license":[{"start":{"date-parts":[[2026,9,4]],"date-time":"2026-09-04T00:00:00Z","timestamp":1788480000000},"content-version":"tdm","delay-in-days":0,"URL":"https:\/\/journals.sagepub.com\/page\/policies\/text-and-data-mining-license"}],"content-domain":{"domain":["journals.sagepub.com"],"crossmark-restriction":true},"short-container-title":["Astrobiology"],"published-print":{"date-parts":[[2026,10,1]]},"abstract":"<jats:p>\n                    The 2.52 Ga Gamohaan Formation in South Africa offers critical insights into microbial ecosystems that inhabited deep-marine environments during the late Archean. Large spheroidal microfossils and pyrite grains preserved in finely laminated black cherts reveal evidence of diverse metabolic processes and a complex deep-marine sulfur cycle. This study combines optical microscopy, scanning electron microscopy, and Raman spectroscopy to characterize fossil kerogen and sedimentary pyrites, along with secondary ion mass spectrometry to analyze their\n                    <jats:italic toggle=\"yes\">in situ<\/jats:italic>\n                    carbon (\u03b4\n                    <jats:sup>13<\/jats:sup>\n                    C) and sulfur (\u03b4\n                    <jats:sup>34<\/jats:sup>\n                    S) isotope compositions, respectively. Raman spectroscopy established the kerogenous composition and thermal maturity of the microfossils.\n                    <jats:italic toggle=\"yes\">In situ<\/jats:italic>\n                    \u03b4\n                    <jats:sup>13<\/jats:sup>\n                    C\n                    <jats:sub>org<\/jats:sub>\n                    values (\u201341.3\u2030 to \u201332.2\u2030) are lower on average than bulk organic matter and define two statistically distinct \u03b4\n                    <jats:sup>13<\/jats:sup>\n                    C\n                    <jats:sub>org<\/jats:sub>\n                    populations, with large spheroidal fossils exhibiting systematically lower values than small spheroids. This size-correlated pattern is consistent with differences in carbon sources, fixation pathways, or ecological setting. Secondary ion mass spectrometry \u03b4\n                    <jats:sup>34<\/jats:sup>\n                    S analyses of pyrite grains (\u20130.7\u2030 to +6.3\u2030) show variability corresponding to differences among pyrite morphologies, consistent with microbial sulfate reduction and further sulfur cycling under sulfate-limited conditions in this deep-marine environment. These isotope data provide an independent geochemical framework for evaluating sulfur-based chemotrophic interpretations of the microfossil assemblage. Collectively, the carbon and sulfur isotope signatures support the presence of a complex benthic sulfur cycle and highlight the ecological and metabolic complexity of offshore marine ecosystems in the Neoarchean.\n                  <\/jats:p>","DOI":"10.1177\/15311074261485886","type":"journal-article","created":{"date-parts":[[2026,9,5]],"date-time":"2026-09-05T02:17:34Z","timestamp":1788574654000},"page":"851-867","update-policy":"https:\/\/doi.org\/10.1177\/sage-journals-update-policy","source":"Crossref","is-referenced-by-count":1,"title":["Carbon and Sulfur Isotopes of Microfossils and Pyrites from Neoarchean Cherts: Microbial Diversity in an Ancient Deep-Marine Environment"],"prefix":"10.1177","volume":"26","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-8523-0072","authenticated-orcid":false,"given":"Jeffrey T.","family":"Osterhout","sequence":"first","affiliation":[{"name":"Department of Geosciences, University of Cincinnati, Cincinnati, Ohio, USA."},{"name":"Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California, USA."}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Andrew D.","family":"Czaja","sequence":"additional","affiliation":[{"name":"Department of Geosciences, University of Cincinnati, Cincinnati, Ohio, USA."}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Kenneth H.","family":"Williford","sequence":"additional","affiliation":[{"name":"Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California, USA."},{"name":"Blue Marble Space Institute of Science, Seattle, Washington, USA."}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Kouki","family":"Kitajima","sequence":"additional","affiliation":[{"name":"Department of Geoscience, University of Wisconsin, Madison, Wisconsin, USA."}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"179","published-online":{"date-parts":[[2026,9,4]]},"reference":[{"key":"e_1_3_3_2_1","doi-asserted-by":"publisher","DOI":"10.1038\/nature04764"},{"key":"e_1_3_3_3_1","doi-asserted-by":"publisher","DOI":"10.1016\/S0037-0738(98)00034-7"},{"key":"e_1_3_3_4_1","doi-asserted-by":"publisher","DOI":"10.1016\/0301-9268(95)00018-Z"},{"key":"e_1_3_3_5_1","doi-asserted-by":"publisher","DOI":"10.1089\/ast.2008.0314"},{"key":"e_1_3_3_6_1","doi-asserted-by":"publisher","DOI":"10.1186\/1471-2148-4-44"},{"key":"e_1_3_3_7_1","doi-asserted-by":"publisher","DOI":"10.5382\/Rev.15.01"},{"key":"e_1_3_3_8_1","doi-asserted-by":"publisher","DOI":"10.1016\/0037-0738(87)90002-9"},{"key":"e_1_3_3_9_1","doi-asserted-by":"publisher","DOI":"10.1126\/science.11536492"},{"key":"e_1_3_3_10_1","doi-asserted-by":"publisher","DOI":"10.1098\/rstb.2008.0041"},{"key":"e_1_3_3_11_1","doi-asserted-by":"publisher","DOI":"10.1126\/science.288.5466.65"},{"key":"e_1_3_3_12_1","doi-asserted-by":"publisher","DOI":"10.2138\/gsrmg.43.1.607"},{"key":"e_1_3_3_13_1","doi-asserted-by":"publisher","DOI":"10.2475\/ajs.304.10.839"},{"key":"e_1_3_3_14_1","doi-asserted-by":"publisher","DOI":"10.1080\/01490457909377735"},{"key":"e_1_3_3_15_1","doi-asserted-by":"publisher","DOI":"10.1130\/G38150.1"},{"key":"e_1_3_3_16_1","doi-asserted-by":"publisher","DOI":"10.2138\/gsrmg.43.1.555"},{"key":"e_1_3_3_17_1","doi-asserted-by":"publisher","DOI":"10.1073\/pnas.060754010"},{"key":"e_1_3_3_18_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.precamres.2017.09.018"},{"key":"e_1_3_3_19_1","doi-asserted-by":"publisher","DOI":"10.1016\/S0012-821X(03)00296-6"},{"key":"e_1_3_3_20_1","doi-asserted-by":"publisher","DOI":"10.1146\/annurev-earth-060313-054802"},{"key":"e_1_3_3_21_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.precamres.2008.10.010"},{"key":"e_1_3_3_22_1","doi-asserted-by":"publisher","DOI":"10.1080\/08120099.2011.607849"},{"key":"e_1_3_3_23_1","doi-asserted-by":"publisher","DOI":"10.3389\/fmicb.2016.00603"},{"key":"e_1_3_3_24_1","doi-asserted-by":"publisher","DOI":"10.1186\/1471-2164-8-86"},{"key":"e_1_3_3_25_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.precamres.2009.02.003"},{"key":"e_1_3_3_26_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.precamres.2012.09.023"},{"key":"e_1_3_3_27_1","doi-asserted-by":"publisher","DOI":"10.1130\/0091-7613(2001)029<0555:IFBSRN>2.0.CO;2"},{"key":"e_1_3_3_28_1","doi-asserted-by":"publisher","DOI":"10.1126\/science.1078265"},{"key":"e_1_3_3_29_1","first-page":"220","volume-title":"Early Life on Earth","author":"Hayes JM","year":"1994","unstructured":"Hayes JM. Global methanotrophy at the Archean\u2013Proterozoic transition. In: Early Life on Earth (Bengtson S. ed.) Columbia University Press: New York, 1994; pp. 220\u2013236."},{"key":"e_1_3_3_30_1","doi-asserted-by":"publisher","DOI":"10.1016\/S0016-7037(02)00950-X"},{"key":"e_1_3_3_31_1","doi-asserted-by":"publisher","DOI":"10.1130\/G34055.1"},{"key":"e_1_3_3_32_1","doi-asserted-by":"publisher","DOI":"10.1038\/nature08793"},{"key":"e_1_3_3_33_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.earscirev.2011.02.003"},{"key":"e_1_3_3_34_1","doi-asserted-by":"publisher","DOI":"10.1111\/j.1472-4669.2006.00091.x"},{"key":"e_1_3_3_35_1","doi-asserted-by":"publisher","DOI":"10.1099\/00221287-34-2-195"},{"key":"e_1_3_3_36_1","doi-asserted-by":"publisher","DOI":"10.1038\/nature01902"},{"key":"e_1_3_3_37_1","doi-asserted-by":"publisher","DOI":"10.1016\/0301-9268(87)90018-0"},{"key":"e_1_3_3_38_1","doi-asserted-by":"publisher","DOI":"10.1130\/0016-7606(2003)115<0566:HACTIF>2.0.CO;2"},{"key":"e_1_3_3_39_1","doi-asserted-by":"publisher","DOI":"10.1016\/0012-821X(78)90011-0"},{"key":"e_1_3_3_40_1","doi-asserted-by":"publisher","DOI":"10.2138\/am-1998-11-1234"},{"key":"e_1_3_3_41_1","doi-asserted-by":"publisher","DOI":"10.1111\/iar.12057"},{"key":"e_1_3_3_42_1","doi-asserted-by":"publisher","DOI":"10.1038\/nature06587"},{"key":"e_1_3_3_43_1","doi-asserted-by":"publisher","DOI":"10.3390\/min13020227"},{"key":"e_1_3_3_44_1","doi-asserted-by":"publisher","DOI":"10.2113\/gselements.11.6.415"},{"key":"e_1_3_3_45_1","doi-asserted-by":"publisher","DOI":"10.1038\/nature13068"},{"key":"e_1_3_3_46_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.epsl.2022.117941"},{"key":"e_1_3_3_47_1","doi-asserted-by":"publisher","DOI":"10.1016\/0016-7037(94)90518-5"},{"key":"e_1_3_3_48_1","doi-asserted-by":"publisher","DOI":"10.1111\/j.1472-4669.2007.00118.x"},{"key":"e_1_3_3_49_1","doi-asserted-by":"publisher","DOI":"10.1139\/cjes-2018-0309"},{"key":"e_1_3_3_50_1","doi-asserted-by":"publisher","DOI":"10.1146\/annurev-earth-072020-055249"},{"key":"e_1_3_3_51_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.epsl.2020.116092"},{"key":"e_1_3_3_52_1","doi-asserted-by":"publisher","DOI":"10.1126\/science.1145861"},{"key":"e_1_3_3_53_1","doi-asserted-by":"publisher","DOI":"10.1038\/ngeo2122"},{"key":"e_1_3_3_54_1","doi-asserted-by":"publisher","DOI":"10.1016\/S0016-7037(97)00333-5"},{"key":"e_1_3_3_55_1","doi-asserted-by":"publisher","DOI":"10.1021\/es404808r"},{"key":"e_1_3_3_56_1","doi-asserted-by":"publisher","DOI":"10.1128\/aem.53.8.1940-1943.1987"},{"key":"e_1_3_3_57_1","doi-asserted-by":"publisher","DOI":"10.1016\/S0301-9268(00)00128-5"},{"key":"e_1_3_3_58_1","doi-asserted-by":"publisher","DOI":"10.1073\/pnas.1718063115"},{"key":"e_1_3_3_59_1","doi-asserted-by":"publisher","DOI":"10.1089\/ast.2005.5.333"},{"key":"e_1_3_3_60_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.precamres.2007.04.009"},{"key":"e_1_3_3_61_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.precamres.2017.07.021"},{"key":"e_1_3_3_62_1","doi-asserted-by":"publisher","DOI":"10.1098\/rstb.2006.1834"},{"key":"e_1_3_3_63_1","doi-asserted-by":"publisher","DOI":"10.1111\/j.1365-3121.2008.00795.x"},{"key":"e_1_3_3_64_1","doi-asserted-by":"publisher","DOI":"10.1126\/science.284.5413.4"},{"key":"e_1_3_3_65_1","doi-asserted-by":"publisher","DOI":"10.1007\/0-387-30746-X_47"},{"key":"e_1_3_3_66_1","doi-asserted-by":"publisher","DOI":"10.1038\/35065071"},{"key":"e_1_3_3_67_1","doi-asserted-by":"publisher","DOI":"10.1016\/S0012-8252(03)00054-0"},{"key":"e_1_3_3_68_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.epsl.2009.01.018"},{"key":"e_1_3_3_69_1","doi-asserted-by":"publisher","DOI":"10.1002\/9781444304312.ch4"},{"key":"e_1_3_3_70_1","doi-asserted-by":"publisher","DOI":"10.1016\/S0031-0182(97)00067-9"},{"key":"e_1_3_3_71_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.precamres.2007.03.006"},{"key":"e_1_3_3_72_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.precamres.2009.02.004"},{"key":"e_1_3_3_73_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.precamres.2012.11.005"},{"key":"e_1_3_3_74_1","doi-asserted-by":"publisher","DOI":"10.1111\/gbi.12148"},{"key":"e_1_3_3_75_1","doi-asserted-by":"publisher","DOI":"10.2113\/gssajg.109.1-2.11"},{"key":"e_1_3_3_76_1","doi-asserted-by":"publisher","DOI":"10.1016\/0301-9268(95)00086-0"},{"key":"e_1_3_3_77_1","doi-asserted-by":"publisher","DOI":"10.2475\/ajs.297.5.455"},{"key":"e_1_3_3_78_1","doi-asserted-by":"publisher","DOI":"10.2307\/1543556"},{"key":"e_1_3_3_79_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.margeo.2009.06.001"},{"key":"e_1_3_3_80_1","doi-asserted-by":"publisher","DOI":"10.1080\/00206810109465008"},{"key":"e_1_3_3_81_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.gca.2008.08.026"},{"key":"e_1_3_3_82_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.chemgeo.2014.06.006"},{"key":"e_1_3_3_83_1","doi-asserted-by":"publisher","DOI":"10.1046\/j.1472-4669.2003.00014.x"},{"key":"e_1_3_3_84_1","doi-asserted-by":"publisher","DOI":"10.1038\/ngeo1238"},{"key":"e_1_3_3_85_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.epsl.2010.11.025"},{"key":"e_1_3_3_86_1","doi-asserted-by":"publisher","DOI":"10.1111\/gbi.12554"},{"key":"e_1_3_3_87_1","doi-asserted-by":"publisher","DOI":"10.1111\/j.1462-2920.2008.01653.x"},{"key":"e_1_3_3_88_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.gca.2012.11.005"},{"key":"e_1_3_3_89_1","doi-asserted-by":"publisher","DOI":"10.3389\/fmicb.2016.00964"},{"key":"e_1_3_3_90_1","doi-asserted-by":"publisher","DOI":"10.2475\/001c.116058"},{"key":"e_1_3_3_91_1","doi-asserted-by":"publisher","DOI":"10.2475\/ajs.305.6-8.467"}],"container-title":["Astrobiology"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/journals.sagepub.com\/doi\/pdf\/10.1177\/15311074261485886","content-type":"application\/pdf","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/journals.sagepub.com\/doi\/full-xml\/10.1177\/15311074261485886","content-type":"application\/xml","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/journals.sagepub.com\/doi\/pdf\/10.1177\/15311074261485886","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,10,14]],"date-time":"2026-10-14T05:08:53Z","timestamp":1791954533000},"score":1,"resource":{"primary":{"URL":"https:\/\/journals.sagepub.com\/doi\/10.1177\/15311074261485886"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,9,4]]},"references-count":90,"journal-issue":{"issue":"10","published-print":{"date-parts":[[2026,10,1]]}},"alternative-id":["10.1177\/15311074261485886"],"URL":"https:\/\/doi.org\/10.1177\/15311074261485886","relation":{},"ISSN":["1531-1074","1557-8070"],"issn-type":[{"value":"1531-1074","type":"print"},{"value":"1557-8070","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,9,4]]}}}