LINK<\/strong><\/a><\/p>\n\n\n\n“NASA’s Genesis mission revealed that the Sun is enriched in 16O compared to the Earth and Mars (the Sun’s \u039417O, defined as \u03b417O\u20130.52\u00d7\u03b418O, is \u201328.4 \u00b1 3.6\u2030; McKeegan et al. 2011). Materials as 16O\u2010rich as the Sun are extremely rare in the meteorite record. Here, we describe a Ca\u2010Al\u2010rich inclusion (CAI) from a CM chondrite that is as 16O\u2010enriched as the Sun (\u039417O = \u201329.1 \u00b1 0.7\u2030). This CAI also has large nucleosynthetic anomalies in 48Ca and 50Ti (\u03b4\u2010values are \u20138.1 \u00b1 3.3 and \u201311.7 \u00b1 2.4\u2030, respectively) and shows no clear evidence for incorporation of live 26Al; (26Al\/27Al)0 = (0.03 \u00b1 0.11) \u00d7 10\u20135. Due to their anomalous isotopic characteristics, the rare CAIs consistent with the Genesis value could be among the first materials that formed in the solar system. In contrast to the CAI studied here, the majority of CAIs formed in or interacted with a reservoir characterized by a \u039417O value near \u201323.5\u2030. Combined with 26Al\u201026Mg systematics, the oxygen isotopic compositions of FUN (fractionation and unidentified nuclear effects), UN, and normal CAIs suggest that nebular conditions were favorable for solids to inherit this value for an extended period of time. Many later\u2010formed materials, such as chondrules, planetesimals, and terrestrial planets, formed in reservoirs with \u039417O near 0\u2030. The distribution could be easier to explain if the common CAI value of \u201323.5\u2030, which is consistent with the Genesis value within 3\u03c3, represented the average composition of the protoplanetary disk.”<\/p>\n","protected":false},"excerpt":{"rendered":"
Levke K\u00f6\u00f6p, Kazuhide Nagashima, Andrew M. Davis, Alexander N. Krot Meteoritics & Planetary Science First Published: 27 March 2020 LINK “NASA’s Genesis mission revealed that the Sun is enriched in 16O compared to the Earth…<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[66,18,72,65,57,71],"tags":[238,124,1548,1846,3273,105,107,1845,135,1863,4390],"_links":{"self":[{"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/21746"}],"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=21746"}],"version-history":[{"count":1,"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/21746\/revisions"}],"predecessor-version":[{"id":21747,"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/21746\/revisions\/21747"}],"wp:attachment":[{"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=21746"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=21746"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=21746"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}