{"id":11762,"date":"2017-02-17T11:20:16","date_gmt":"2017-02-17T10:20:16","guid":{"rendered":"http:\/\/karmaka.de\/?p=11762"},"modified":"2017-03-27T16:50:08","modified_gmt":"2017-03-27T14:50:08","slug":"relict-chondrules-in-primitive-achondrites-remnants-from-their-precursor-parent-bodies","status":"publish","type":"post","link":"https:\/\/karmaka.de\/?p=11762","title":{"rendered":"Relict chondrules in primitive achondrites: Remnants from their precursor parent bodies<span class=\"badge-status\" style=\"background:#787878\">OPEN ACCESS<\/span>&nbsp;"},"content":{"rendered":"<p>Devin L. Schrader, Timothy J. McCoy, Kathryn Gardner-Vandy<\/p>\n<p>Geochimica et Cosmochimica Acta<br \/>\nIn Press, Accepted Manuscript, Available online 17 February 2017<\/p>\n<p><a href=\"http:\/\/www.sciencedirect.com\/science\/article\/pii\/S0016703717300893\" target=\"_blank\"><strong>LINK (OPEN ACCESS)<\/strong><\/a> <strong>Free until 6 May 2017<\/strong><\/p>\n<p><a href=\"http:\/\/www.sciencedirect.com\/science\/article\/pii\/S0016703717300893\/pdfft?md5=7ae1301b7bdeba6a059ebc5f7c3eb4c3&#038;pid=1-s2.0-S0016703717300893-main.pdf\" target=\"_blank\"><strong>PDF (OPEN ACCESS)<\/strong><\/a> <strong>Free until 6 May 2017<\/strong><\/p>\n<p>&#8220;We studied the petrography, analyzed the chemical compositions, constrained the closure temperatures (via geothermometry), and determined the oxidation states of relict chondrules in Campo del Cielo (IAB iron meteorite), Graves Nunataks (GRA) 98028 (acapulcoite), and Netscha\u00ebvo (IIE iron meteorite) to constrain their formation conditions and investigate links to known meteorite groups. Despite having been thermally metamorphosed, mineral phases within relict chondrules retain information about their precursor compositions. The sizes and textures of relict chondrules, and silicate and chromite compositions indicate that Campo del Cielo, GRA 98028, and Netscha\u00ebvo had distinct parent bodies that were similar to, but different from, known chondrite groups. To determine the utility of relict chondrule sizes in thermally metamorphosed meteorites, we determined the chondrule size distributions in the LL chondrites Semarkona (LL3.00), Soko-Banja (LL4), Siena (LL5), and Saint-S\u00e9verin (LL6), and the H chondrites Clovis (no. 1) (H3.6), Kesen (H4), Arbol Solo (H5), and Estacado (H6). As expected, mean chondrule diameters increase with degree of thermal metamorphism.<\/p>\n<p>We find that Campo del Cielo and GRA 98028 were reduced during thermal metamorphism, consistent with previous studies, indicating that their precursors were initially more FeO-rich than their current compositions. In contrast to previous studies, we find no evidence for reduction of silicates in Netscha\u00ebvo. Normal zoning of olivine in Netscha\u00ebvo is consistent with crystallization and suggests its silicates are near their primary FeO-contents. The presence of elongated chromite grains along olivine grain boundaries in Netscha\u00ebvo indicates formation during thermal metamorphism under oxidizing conditions. Due to the absence of reduction and the composition of chromite being distinct from that of metamorphosed H chondrites, we conclude that Netscha\u00ebvo, and by extension the IIE iron meteorites, are not from the H chondrite parent body.&#8221;<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Devin L. Schrader, Timothy J. McCoy, Kathryn Gardner-Vandy Geochimica et Cosmochimica Acta In Press, Accepted Manuscript, Available online 17 February 2017 LINK (OPEN ACCESS) Free until 6 May 2017 PDF (OPEN ACCESS) Free until 6&#8230;<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[30,56,1607,6,371,419,214,24,137,29,62],"tags":[3675,377,320,3183,3673,3352,3669,3674,3676,2327,2587,3668,3672,158,3671,3670,1843],"_links":{"self":[{"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/11762"}],"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=11762"}],"version-history":[{"count":4,"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/11762\/revisions"}],"predecessor-version":[{"id":12152,"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/11762\/revisions\/12152"}],"wp:attachment":[{"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=11762"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=11762"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=11762"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}