{"id":27363,"date":"2021-04-16T07:37:46","date_gmt":"2021-04-16T05:37:46","guid":{"rendered":"https:\/\/karmaka.de\/?p=27363"},"modified":"2022-01-08T09:59:53","modified_gmt":"2022-01-08T08:59:53","slug":"the-loongana-cl-group-of-carbonaceous-chondrites","status":"publish","type":"post","link":"https:\/\/karmaka.de\/?p=27363","title":{"rendered":"The Loongana (CL) group of carbonaceous chondrites<span class=\"badge-status\" style=\"background:#787878\">OPEN ACCESS<\/span>&nbsp;"},"content":{"rendered":"\n<p>Knut Metzler, Dominik C. Hezel, Jens Barosch, Elias W\u00f6lfer, Jonas M. Schneider, Jan L. Hellmann, Jasper Berndt, Andreas Stracke, J\u00e9r\u00f4me Gattacceca, Richard C. Greenwood, Ian A. Franchi, Christoph Burkhardt, Thorsten Kleine<\/p>\n\n\n\n<p>Geochimica et Cosmochimica Acta<br>In Press, Journal Pre-proof, Available online 16 April 2021<\/p>\n\n\n\n<p><a href=\"https:\/\/www.sciencedirect.com\/science\/article\/abs\/pii\/S0016703721002222\" target=\"_blank\" rel=\"noreferrer noopener\"><strong>LINK<\/strong><\/a><\/p>\n\n\n\n<p><a rel=\"noreferrer noopener\" href=\"https:\/\/hal.archives-ouvertes.fr\/hal-03201634\/document\" target=\"_blank\"><strong>PDF (OPEN ACCESS)<\/strong><\/a> Submitted on 22 Oct 2021<\/p>\n\n\n\n<p>&#8220;Highlights<\/p>\n\n\n\n<p>\u2022 Five related meteorites define the Loongana (CL) group of carbonaceous chondrites.<br>\u2022 Coolidge, Loongana 001, LoV 051, NWA 033, and NWA 13400 represent CL chondrites.<br>\u2022 Strongest depletions of volatile elements in the CL group of carbonaceous chondrites.<br>\u2022 Unique positions of carbonaceous chondrites of the CL group in a \u03b554Cr- \u03b550Ti diagram.<br>\u2022 Enrichment of 16O in some CL chondrites compared to CO, CV, and CK chondrites.&#8221;<\/p>\n\n\n\n<p class=\"justify-text\">&#8220;A coordinated study of the petrology, mineral chemistry, and bulk chemical and isotopic composition of the five ungrouped carbonaceous chondrites Coolidge, Loongana 001, Los Vientos (LoV) 051, Northwest Africa (NWA) 033, and NWA 13400 reveals that these meteorites have a similar set of properties that distinguishes them from the other carbonaceous chondrite groups and allows definition of the new Loongana (CL) group of carbonaceous chondrites. The basic characteristics of the investigated samples are: (1) Lithophile element ratios (e.g., Al\/Mg, Si\/Mg) are within the typical range of other carbonaceous chondrite groups. (2) Fe-Ni metal abundances are considerably higher than for CV, but similar to CR chondrites. (3) Chondrule size-frequency distributions are similar to CV, but dissimilar to CR chondrites. (4) The mean CAI abundance is \u223c1.4 vol%, i.e., lower than in CV but much higher than in CR chondrites. (5) Very low amounts of matrix (17-21 vol%), the lowest among the main carbonaceous chondrite groups (CI, CM, CO, CV, CR, CK). (6) Olivine is nearly equilibrated, with mean fayalite (Fa) values between 12.5 mol% (Loongana 001) and 14.7 mol% (NWA 13400) as a metamorphic effect. (7) Lower Al2O3 and higher MgO and Cr2O3 concentrations in matrix, compared to matrix in CV, CK, and CR chondrites. (8) Volatile elements (Mn, Na, K, Rb, Cs, Zn, Se, Te, Pb, Tl) are considerably depleted compared to all other main carbonaceous chondrite groups, reflecting the low matrix abundance. (9) Bulk O isotope compositions plot along the CCAM line (\u039417O -3.96 to -5.47\u2030), partly overlapping with the CV and CK chondrite field but including samples that are more 16O-rich. (10) Unique positions of CL values in the \u045454Cr-\u045450Ti isotope plot, with \u045454Cr values similar to CV, CK, and CO, but \u045450Ti values similar to CR chondrites. All CL chondrites studied here are of petrologic type 3.9 to 4, indicating that they have been thermally metamorphosed on the parent body. The diagnostic features of CL chondrites detailed here provide a basis for identifying CL members of lower petrologic types. Such samples will be important for determining the pristine state of these meteorites and their components.&#8221;<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Knut Metzler, Dominik C. Hezel, Jens Barosch, Elias W\u00f6lfer, Jonas M. Schneider, Jan L. Hellmann, Jasper Berndt, Andreas Stracke, J\u00e9r\u00f4me Gattacceca, Richard C. Greenwood, Ian A. Franchi, Christoph Burkhardt, Thorsten Kleine Geochimica et Cosmochimica ActaIn&#8230;<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[9,59,343],"tags":[3273,5898,346,5922,5921,5920,5923],"_links":{"self":[{"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/27363"}],"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=27363"}],"version-history":[{"count":3,"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/27363\/revisions"}],"predecessor-version":[{"id":29921,"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/27363\/revisions\/29921"}],"wp:attachment":[{"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=27363"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=27363"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=27363"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}