{"id":20275,"date":"2019-08-13T06:53:14","date_gmt":"2019-08-13T04:53:14","guid":{"rendered":"http:\/\/karmaka.de\/?p=20275"},"modified":"2019-08-13T06:53:19","modified_gmt":"2019-08-13T04:53:19","slug":"cr-isotopes-in-physically-separated-components-of-the-allende-cv3-and-murchison-cm2-chondrites-implications-for-isotopic-heterogeneity-in-the-solar-nebula-and-parent-body-processes","status":"publish","type":"post","link":"https:\/\/karmaka.de\/?p=20275","title":{"rendered":"Cr isotopes in physically separated components of the Allende CV3 and Murchison CM2 chondrites: Implications for isotopic heterogeneity in the solar nebula and parent body processes<span class=\"badge-status\" style=\"background:#787878\">OPEN ACCESS<\/span>&nbsp;"},"content":{"rendered":"\n<p>Yogita Kadlag, Harry Becker, Andreas Harbott<\/p>\n\n\n\n<p>Meteoritics &amp; Planetary Science<br>\nFirst Published: 12 August 2019<\/p>\n\n\n\n<p><a href=\"https:\/\/onlinelibrary.wiley.com\/doi\/full\/10.1111\/maps.13375\" target=\"_blank\" rel=\"noreferrer noopener\"><strong>LINK (OPEN ACCESS)<\/strong><\/a><br>\n<a href=\"https:\/\/onlinelibrary.wiley.com\/doi\/pdf\/10.1111\/maps.13375\" target=\"_blank\" rel=\"noreferrer noopener\"><strong>PDF (OPEN ACCESS)<\/strong><\/a><\/p>\n\n\n\n<p class=\"justify-text\">&#8220;Chromium isotopic data of physically separated components (chondrules, CAIs, variably magnetic size fractions) of the carbonaceous chondrites Allende and Murchison and bulk rock data of Allende, Ivuna, and Orgueil are reported to evaluate the origin of isotopic heterogeneity in these meteorites. Allende components show \u03b553Cr and \u03b554Cr from \u22120.23 \u00b1 0.07 to 0.37 \u00b1 0.05 and from \u22120.43 \u00b1 0.08 to 3.7 \u00b1 0.1, respectively. In components of Murchison, \u03b553Cr and \u03b554Cr vary from \u22120.06 \u00b1 0.08 to 0.5 \u00b1 0.1 and from 0.7 \u00b1 0.2 to 1.7 \u00b1 0.1, respectively. The non\u2010systematic variations of \u03b553Cr and 55Mn\/52Cr in the components of Allende and Murchison were likely caused by small\u2010scale, alteration\u2010related redistribution of Mn &gt;20 Ma after formation of the solar system. Chondrule fractions show the lowest 55Mn\/52Cr and \u03b554Cr values of all components, consistent with evaporation of Mn and \u03b554Cr\u2010rich carrier phases from chondrule precursors. Components other than the chondrules show higher Mn\/Cr and \u03b554Cr, suggestive of chemical and isotopic complementarity between chondrules and matrix\u2010rich fractions. Bulk rock compositions calculated based on weighted compositions of components agree with measured Cr isotope data of bulk rocks, in spite of the Cr isotopic heterogeneity reported by the present and previous studies. This indicates that on a sampling scale comprising several hundred milligrams, these meteorites sampled isotopically and chemically homogeneous nebular reservoirs. The linear correlation of 55Mn\/52Cr with \u03b553Cr in bulk rocks likely was caused by variable fractionation of Mn\/Cr, subsequent mixing of phases in nebular domains, and radiogenic ingrowth of 53Cr.&#8221;<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Yogita Kadlag, Harry Becker, Andreas Harbott Meteoritics &amp; Planetary Science First Published: 12 August 2019 LINK (OPEN ACCESS) PDF (OPEN ACCESS) &#8220;Chromium isotopic data of physically separated components (chondrules, CAIs, variably magnetic size fractions) of&#8230;<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[66,9,56,10,18,14,72,71],"tags":[2270,5139,108,1846,1839,1564,2268,1175,734,231,107,110],"_links":{"self":[{"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/20275"}],"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=20275"}],"version-history":[{"count":1,"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/20275\/revisions"}],"predecessor-version":[{"id":20276,"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/20275\/revisions\/20276"}],"wp:attachment":[{"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=20275"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=20275"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=20275"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}