{"id":3892,"date":"2015-02-21T17:30:26","date_gmt":"2015-02-21T16:30:26","guid":{"rendered":"http:\/\/karmaka.de\/?p=3892"},"modified":"2017-03-08T18:24:58","modified_gmt":"2017-03-08T17:24:58","slug":"hf-w-chronology-of-the-eucrite-parent-body","status":"publish","type":"post","link":"https:\/\/karmaka.de\/?p=3892","title":{"rendered":"Hf-W chronology of the eucrite parent body"},"content":{"rendered":"<p>Mathieu Touboul, Peter Sprung, Sarah A. Aciego, Bernard Bourdon, Thorsten Kleine<\/p>\n<p>Geochimica et Cosmochimica Acta<br \/>\navailable online 21 February 2015<br \/>\ndoi:10.1016\/j.gca.2015.02.018<\/p>\n<p><a href=\"http:\/\/www.sciencedirect.com\/science\/article\/pii\/S0016703715001015\" target=\"_blank\"><strong>LINK<\/strong><\/a><\/p>\n<div class=\"su-quote su-quote-style-default\"><div class=\"su-quote-inner su-u-clearfix su-u-trim\">The 182Hf-182W systematics of 12 whole-rock eucrites, including basaltic and cumulate samples, have been investigated. The Hf-W isotope systematics of both basaltic and cumulate eucrites are consistent with derivation from a single mantle source characterized by a strongly suprachondritic Hf\/W ratio (180Hf\/184W of \u223c19). The elevated Hf\/W of this mantle source was established by core formation within \u223c1 Ma after CAI formation or, alternatively, represents that of the residual melt of a magma ocean from which the eucrites ultimately formed. In the latter case the time of core formation is more uncertain and core formation may have occurred slightly later than \u223c1 Ma. The investigated basaltic eucrites fall into three distinct age groups with Hf-W ages of \u223c4 Ma (Stannern), \u223c11 Ma (Bereba, Bouvante) and \u223c22 Ma (Camel Donga, Juvinas) after CAI formation and provide evidence for a protracted history of magmatism and crustal metamorphism on the eucrite parent body, lasting for at least \u223c20 Ma. Evidence for even later activity is provided by the cumulate eucrites, which exhibit only small if any variations in 182W\/184W in spite of variable 180Hf\/184W, indicating cooling below the Hf-W closure temperature when 182Hf was nearly extinct. On the basis of three cumulate eucrites, a Hf-W age of 38\u00b121 Ma is inferred, but even younger ages would also be consistent with the Hf-W data.<\/div><\/div>\n","protected":false},"excerpt":{"rendered":"<p>Mathieu Touboul, Peter Sprung, Sarah A. Aciego, Bernard Bourdon, Thorsten Kleine Geochimica et Cosmochimica Acta available online 21 February 2015 doi:10.1016\/j.gca.2015.02.018 LINK<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[35,33,137],"tags":[1061,852,1060,1062,1063,1064,1823,3628,422,355,356],"_links":{"self":[{"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/3892"}],"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=3892"}],"version-history":[{"count":2,"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/3892\/revisions"}],"predecessor-version":[{"id":3894,"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/3892\/revisions\/3894"}],"wp:attachment":[{"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=3892"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=3892"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=3892"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}