{"id":31343,"date":"2022-10-06T21:22:19","date_gmt":"2022-10-06T19:22:19","guid":{"rendered":"https:\/\/karmaka.de\/?p=31343"},"modified":"2022-10-06T21:22:20","modified_gmt":"2022-10-06T19:22:20","slug":"the-cadmium-and-zinc-isotope-compositions-of-the-silicate-earth-implications-for-terrestrial-volatile-accretion","status":"publish","type":"post","link":"https:\/\/karmaka.de\/?p=31343","title":{"rendered":"The cadmium and zinc isotope compositions of the silicate Earth \u2013 implications for terrestrial volatile accretion<span class=\"badge-status\" style=\"background:#787878\">OPEN ACCESS<\/span>&nbsp;"},"content":{"rendered":"\n<p>Harvey Pickard, Emeliana Palk, Maria Sch\u00f6nb\u00e4chler, Rebekah E.T. Moore, Barry J. Coles, Katharina Kreissig, Katrina Nilsson-Kerr, Samantha J. Hammond, Eiichi Takazawa, Christophe H\u00e9mond, Peter Tropper, Dan N. Barfod, Mark Rehk\u00e4mper<\/p>\n\n\n\n<p>Geochimica et Cosmochimica Acta<br>Available online 6 October 2022<\/p>\n\n\n\n<p><a href=\"https:\/\/www.sciencedirect.com\/science\/article\/pii\/S0016703722005282\" target=\"_blank\" rel=\"noreferrer noopener\"><strong>LINK (OPEN ACCESS)<\/strong><\/a><\/p>\n\n\n\n<p class=\"justify-text\">&#8220;Zinc and Cd isotope compositions are presented for a comprehensive suite of terrestrial rocks to constrain the extent of Zn and Cd isotope fractionation during igneous processes and better define the \u03b466Zn and \u03b4114Cd values of the silicate Earth (the \u03b4 values denote per mille deviations of 66Zn\/64Zn from JMC Lyon Zn and of 114Cd\/110Cd from NIST SRM 3108 Cd). Analyses of spinel lherzolites provide a bulk silicate Earth (BSE) \u03b4114CdBSE value of \u20130.06 \u00b1 0.03\u2030 (2SD). For Zn, the peridotite data of the current and previous studies define a mean \u03b466ZnBSE = 0.20 \u00b1 0.05\u2030 (2SD). Komatiite analyses of this and published investigations yield similar mean values, which suggests that the Zn and Cd isotope compositions of the mantle remained fairly constant since the Archean. Data for loess provide upper continental crust compositions of \u03b4114Cd = 0.03 \u00b1 0.10\u2030 and \u03b466Zn = 0.23 \u00b1 0.07\u2030. The Zn isotope and abundance data for peridotites and oceanic basalts are in accord with the previous observation of a mantle array, with basalts having higher Zn concentrations and \u03b466Zn values than the peridotites. To a first order, this reflects slightly incompatible behaviour of Zn during mantle melting and melt differentiation with associated enrichment of heavy Zn isotopes in the melt phase. Cadmium is marginally more incompatible than Zn during igneous processes and the oceanic basalts also display a minor enrichment of heavy Cd isotopes relative to peridotites. However, secondary processes produce significant Cd isotope variability in both mantle melts and peridotites, obscuring the primary igneous array. The \u03b466ZnBSE estimates of this and previous studies resemble the Zn isotope compositions of CV and CO carbonaceous and some enstatite chondrites. In contrast, the BSE has a lower \u03b4114CdBSE value than enstatite and carbonaceous chondrites. This implies that the Cd isotope composition of the BSE was either fractionated during accretion or that Earth\u2019s Cd inventory was not exclusively acquired from material related to carbonaceous and enstatite chondrites. Importantly, delivery of Zn and Cd to the BSE solely by CI and CM chondrites is not in accord with the meteorite and terrestrial stable isotope data of these elements.&#8221;<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Harvey Pickard, Emeliana Palk, Maria Sch\u00f6nb\u00e4chler, Rebekah E.T. Moore, Barry J. Coles, Katharina Kreissig, Katrina Nilsson-Kerr, Samantha J. Hammond, Eiichi Takazawa, Christophe H\u00e9mond, Peter Tropper, Dan N. Barfod, Mark Rehk\u00e4mper Geochimica et Cosmochimica ActaAvailable online&#8230;<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[131,112],"tags":[4819,5438,369,5660],"_links":{"self":[{"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/31343"}],"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=31343"}],"version-history":[{"count":1,"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/31343\/revisions"}],"predecessor-version":[{"id":31344,"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/31343\/revisions\/31344"}],"wp:attachment":[{"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=31343"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=31343"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=31343"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}