LINK<\/strong><\/a><\/p>\n“The excess of highly siderophile elements in the Earth\u2019s mantle is thought to reflect the addition of primitive meteoritic material after core formation ceased1, 2, 3, 4. This \u2018late veneer\u2019 either comprises material remaining in the terrestrial planet region after the main stages of the Earth\u2019s accretion5, 6, or derives from more distant asteroidal7 or cometary8 sources. Distinguishing between these disparate origins is important because a late veneer consisting of carbonaceous chondrite-like asteroids7 or comets8 could be the principal source of the Earth\u2019s volatiles and water. Until now, however, a \u2018genetic\u2019 link between the late veneer and such volatile-rich materials has not been established or ruled out. Such genetic links can be determined using ruthenium (Ru) isotopes, because the Ru in the Earth\u2019s mantle predominantly derives from the late veneer9, and because meteorites exhibit Ru isotope variations arising from the heterogeneous distribution of stellar-derived dust10, 11. Although Ru isotopic data and the correlation of Ru and molybdenum (Mo) isotope anomalies in meteorites were previously used to argue that the late veneer derives from the same type of inner Solar System material as do Earth\u2019s main building blocks6, the Ru isotopic composition of carbonaceous chondrites has not been determined sufficiently well to rule them out as a source of the late veneer. Here we show that all chondrites, including carbonaceous chondrites, have Ru isotopic compositions distinct from that of the Earth\u2019s mantle. The Ru isotope anomalies increase from enstatite to ordinary to carbonaceous chondrites, demonstrating that material formed at greater heliocentric distance contains larger Ru isotope anomalies. Therefore, these data refute an outer Solar System origin for the late veneer and imply that the late veneer was not the primary source of volatiles and water on the Earth.”<\/p>\n","protected":false},"excerpt":{"rendered":"
Mario Fischer-G\u00f6dde & Thorsten Kleine Nature 541, 525\u2013527 doi:10.1038\/nature 21045 Published online: 25 January 2017 LINK “The excess of highly siderophile elements in the Earth\u2019s mantle is thought to reflect the addition of primitive meteoritic…<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[131,9,179,112,81],"tags":[3152,642,3290,3554,3423,369,1855],"_links":{"self":[{"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/11315"}],"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=11315"}],"version-history":[{"count":1,"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/11315\/revisions"}],"predecessor-version":[{"id":11316,"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/11315\/revisions\/11316"}],"wp:attachment":[{"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=11315"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=11315"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=11315"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}