{"id":20868,"date":"2019-12-05T07:18:17","date_gmt":"2019-12-05T06:18:17","guid":{"rendered":"http:\/\/karmaka.de\/?p=20868"},"modified":"2019-12-11T12:29:57","modified_gmt":"2019-12-11T11:29:57","slug":"noble-gas-variations-in-ureilites-and-their-implications-for-ureilite-parent-body-formation","status":"publish","type":"post","link":"https:\/\/karmaka.de\/?p=20868","title":{"rendered":"Noble gas variations in ureilites and their implications for ureilite parent body formation<span class=\"badge-status\" style=\"background:#787878\">OPEN ACCESS<\/span>&nbsp;"},"content":{"rendered":"\n<p>Michael W. Broadley, David V. Bekaert, Bernard Marty, Akira Yamaguchi, Jean-Alix Barrat<\/p>\n\n\n\n<p>Geochimica et Cosmochimica Acta<br>\nIn Press, Journal Pre-proof, Available online 5 December 2019<\/p>\n\n\n\n<p><a rel=\"noreferrer noopener\" href=\"https:\/\/www.sciencedirect.com\/science\/article\/pii\/S0016703719307409\" target=\"_blank\"><strong>LINK (OPEN ACCESS)<\/strong><\/a><\/p>\n\n\n\n<p><a href=\"https:\/\/www.sciencedirect.com\/science\/article\/pii\/S0016703719307409\/pdfft?md5=679be3b6a52f141fd9025a9a162e917a&amp;pid=1-s2.0-S0016703719307409-main.pdf\" target=\"_blank\" rel=\"noreferrer noopener\"><strong>PDF (OPEN ACCESS)<\/strong><\/a><\/p>\n\n\n\n<p class=\"justify-text\">&#8220;Ureilites are equilibrated carbon-rich olivine-pyroxene rocks from the partially melted mantle of a large (&gt;500 km diameter) heterogeneous parent body. Recently the ureilite parent body was interpreted as an incomplete mixture of material from two carbon-rich chondritic reservoirs, one (Mg-rich) with reduced iron, low \u039417O and low \u03b413C, and the other with oxidised iron, high \u039417O and high \u03b413C. Here we analyse noble gases (Ar, Kr and Xe) in six equilibrated (unbrecciated) ureilites from Northwest Africa (NWA 2236, NWA 7686, NWA 8049, NWA 8172, NWA 11032 and NWA 11368). We observe weak positive and negative correlations of \u039417O and Mg# with the elemental ratios of Ar\/Xe and Kr\/Xe, respectively, as well as a weak positive correlation of Mg# with the heavy isotopes of Xe. These correlations broadly support the idea of the two-component mixing hypothesis. Our analyses further suggest that the Mg-rich endmember was rich in Xe from presolar grains (HL-Xe) while the Mg-poorer component may have contained solar-derived noble gases. The observed correlations are less straightforward to reconcile with a recent model for the origin of the ureilite parent body, involving oxidation of metal by H2O from accreted ice with \u2018heavy\u2019 oxygen isotopes.&#8221;<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Michael W. Broadley, David V. Bekaert, Bernard Marty, Akira Yamaguchi, Jean-Alix Barrat Geochimica et Cosmochimica Acta In Press, Journal Pre-proof, Available online 5 December 2019 LINK (OPEN ACCESS) PDF (OPEN ACCESS) &#8220;Ureilites are equilibrated carbon-rich&#8230;<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[137,39],"tags":[5304,5307,5302,5305,5303,5306,245,1952],"_links":{"self":[{"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/20868"}],"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=20868"}],"version-history":[{"count":5,"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/20868\/revisions"}],"predecessor-version":[{"id":20928,"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/20868\/revisions\/20928"}],"wp:attachment":[{"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=20868"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=20868"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=20868"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}