LINK<\/strong><\/a><\/p>\n\n\n\n“The sulfur isotope budget of Martian regolith breccia (NWA 7533) has been addressed from conventional fluorination bulk rock analyses and ion microprobe in situ analyses. The bulk rock analyses yield 865 \u00b1 50 ppm S in agreement with LA\u2010ICP\u2010MS analyses. These new data support previous estimates of 80% S loss resulting from terrestrial weathering of NWA 7533 pyrite. Pyrite is by far the major S host. Apatite and Fe oxyhydroxides are negligible S carriers, as are the few tiny igneous pyrrhotite\u2013pentlandite sulfide grains included in lithic clasts so far identified. A small nonzero \u039433S (\u22120.029 \u00b1 0.010\u2030) signal is clearly resolved at the 2\u03c3 level in the bulk rock analyses, coupled with negative CDT\u2010normalized \u03b434S (\u22122.54 \u00b1 0.10\u2030), and near\u2010zero \u039436S (0.002 \u00b1 0.09\u2030). In situ analyses also yield negative \u039433S values (\u22120.05 to \u22120.30\u2030) with only a few positive \u039433S up to +0.38\u2030. The slight discrepancy compared to the bulk rock results is attributed to a possible sampling bias. The occurrence of mass\u2010independent fractionation (MIF) supports a model of NWA 7533 pyrite formation from surface sulfur that experienced photochemical reaction(s). The driving force that recycled crustal S in NWA 7533 lithologies\u2014magmatic intrusions or impact\u2010induced heat\u2014is presently unclear. However, in situ analyses also gave negative \u03b434S values (+1 to \u22125.8\u2030). Such negative values in the hydrothermal setting of NWA 7533 are reflective of hydrothermal sulfides precipitated from H2S\/HS\u2010 aqueous fluid produced via open\u2010system thermochemical reduction of sulfates at high temperatures (>300 \u00b0C). “<\/p>\n","protected":false},"excerpt":{"rendered":"
Jean\u2010Pierre Lorand Jabrane Labidi Claire Rollion\u2010Bard Emilie Thomassot Jeremy J. Bellucci Martin Whitehouse Alexander Nemchin Munir Humayun James Farquhar Roger H. Hewins Brigitte Zanda Sylvain Pont Meteoritics & Planetary ScienceVersion of Record online:08 September 2020…<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[122,42,46],"tags":[1828,352,359,317],"_links":{"self":[{"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/23779"}],"collection":[{"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=23779"}],"version-history":[{"count":1,"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/23779\/revisions"}],"predecessor-version":[{"id":23780,"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/23779\/revisions\/23780"}],"wp:attachment":[{"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=23779"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=23779"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=23779"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}