{"id":19632,"date":"2019-05-25T00:45:37","date_gmt":"2019-05-24T22:45:37","guid":{"rendered":"http:\/\/karmaka.de\/?p=19632"},"modified":"2019-05-25T00:47:04","modified_gmt":"2019-05-24T22:47:04","slug":"syneruptive-incorporation-of-martian-surface-sulphur-in-the-nakhlite-lava-flows-revealed-by-s-and-os-isotopes-and-highly-siderophile-elements-implication-for-mantle-sources-in-mars","status":"publish","type":"post","link":"https:\/\/karmaka.de\/?p=19632","title":{"rendered":"Syneruptive incorporation of martian surface sulphur in the nakhlite lava flows revealed by S and Os isotopes and highly siderophile elements: implication for mantle sources in MarsOPEN ACCESS<\/span> "},"content":{"rendered":"\n

N. Mari, A.J.V. Riches, L.J. Hallis, Y. Marrocchi, J. Villeneuve, P. Gleissner, H. Becker, M.R. Lee<\/p>\n\n\n\n

Geochimica et Cosmochimica Acta
\nIn Press, Accepted Manuscript, Available online 24 May 2019<\/p>\n\n\n\n

LINK (OPEN ACCESS)<\/strong><\/a><\/p>\n\n\n\n

PDF (OPEN ACCESS)<\/strong><\/a><\/p>\n\n\n\n

“Martian lava flows likely acquired S-rich material from the regolith during their emplacement on the planet\u2019s surface. We investigated five of the twenty known nakhlites (Nakhla, Lafayette, Miller Range (MIL) 090032, Yamato 000593, and Yamato 000749) to determine whether these lavas show evidence of regolith assimilation, and to constrain the potential implications that this process has on chemical tracing of martian mantle source(s). To establish the proportionate influence of atmospheric, hydrothermal, and volcanic processes on nakhlite isotopic systematics we obtained in situ sulphur isotope data (\u039433S and \u03b434S) for sulphide grains (pyrrhotite and pyrite) in all five nakhlite samples. For Nakhla, Lafayette, and MIL 090032, these data are integrated with highly siderophile element (HSE) abundances and Os-isotope compositions, as well as textural information constrained prior to isotopic analysis. This work thereby provides the first Re-Os isotope systematics for two different nakhlites, and also the first Re-Os isotope data for martian sample for which detailed petrographic information was constrained prior to digestion.<\/p>\n\n\n\n

We report the largest variation in \u03b434S yet found in martian meteorites (-13.20 \u2030 to +15.16 \u2030). The relatively positive \u039433S and \u03b434S values of MIL 090032 (\u03b434S = +10.54 \u00b1 0.09 \u2030; \u039433S = -0.67 \u00b1 0.10 \u2030) indicate this meteorite assimilated sulphur affected by UV-photochemistry. In contrast, the strongly negative values of Lafayette (\u03b434S = -10.76 \u00b1 0.14 \u2030; \u039433S = -0.09 \u00b1 0.12 \u2030) are indicative of hydrothermal processes on Mars. Nakhla, Yamato 000593, and Yamato 000749 sulphides have a narrower range of sulphur isotope compositions (\u039433S and \u03b434S \u223c 0) that is consistent with no assimilation of martian surface materials during lava flow emplacement. Consequently we used this second group of \u039433S values to approximate the \u039433S of the nakhlite source, yielding a \u039433S value of -0.1 \u2030.<\/p>\n\n\n\n

Nakhlite HSE patterns result from a sulphide-saturated melt where Ru-Os-Ir alloys\/sulphide were likely crystallized during earlier phases of magmatic processing in Mars to result in the fractionated HSE patterns of the nakhlites. Our data, alongside a synthesis of previously published data, suggest assimilation of an enriched component to the primary nakhlite melt, potentially a late-stage crystallization cumulate from the martian magma ocean stage. In the context of this model, and within large uncertainties, our data hint at perturbation and potential decoupling of nakhlite Re-Os isotope systematics from other isotopic systems as a result of small degrees of assimilation of a regolith component with highly radiogenic 187Os\/188Os.”<\/p>\n","protected":false},"excerpt":{"rendered":"

N. Mari, A.J.V. Riches, L.J. Hallis, Y. Marrocchi, J. Villeneuve, P. Gleissner, H. Becker, M.R. Lee Geochimica et Cosmochimica Acta In Press, Accepted Manuscript, Available online 24 May 2019 LINK (OPEN ACCESS) PDF (OPEN ACCESS)…<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[122,42,44],"tags":[4985,634,1858,1920,4986,383,4987,4221,1634],"_links":{"self":[{"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/19632"}],"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=19632"}],"version-history":[{"count":2,"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/19632\/revisions"}],"predecessor-version":[{"id":19634,"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/19632\/revisions\/19634"}],"wp:attachment":[{"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=19632"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=19632"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=19632"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}