{"id":27632,"date":"2021-05-01T12:03:09","date_gmt":"2021-05-01T10:03:09","guid":{"rendered":"https:\/\/karmaka.de\/?p=27632"},"modified":"2021-05-01T12:03:10","modified_gmt":"2021-05-01T10:03:10","slug":"carbonate-assemblages-in-cold-bokkeveld-cm-chondrite-reveal-complex-parent-body-evolution","status":"publish","type":"post","link":"https:\/\/karmaka.de\/?p=27632","title":{"rendered":"Carbonate assemblages in Cold Bokkeveld CM chondrite reveal complex parent body evolution<span class=\"badge-status\" style=\"background:#787878\">OPEN ACCESS<\/span>&nbsp;"},"content":{"rendered":"\n<p>Stefan Farsang, Ian A. Franchi, Xuchao Zhao, Timothy D. Raub, Simon A.T. Redfern, Monica M. Grady<\/p>\n\n\n\n<p>Meteoritics &amp; Planetary Science<br>Version of Record online: 01 May 2021<\/p>\n\n\n\n<p><a href=\"https:\/\/onlinelibrary.wiley.com\/doi\/10.1111\/maps.13647\" target=\"_blank\" rel=\"noreferrer noopener\"><strong>LINK (OPEN ACCESS)<\/strong><\/a><br><a href=\"https:\/\/onlinelibrary.wiley.com\/doi\/epdf\/10.1111\/maps.13647\" target=\"_blank\" rel=\"noreferrer noopener\"><strong>PDF (OPEN ACCESS)<\/strong><\/a><\/p>\n\n\n\n<p class=\"justify-text\">&#8220;The paragenesis of carbonates in the Cold Bokkeveld CM chondrite is determined from a detailed petrographic, chemical, spectroscopic, and isotopic study of nine associations of carbonates (aragonite, calcite, and dolomite) with other secondary minerals that occur within the meteorite. Our study reveals the existence of carbonates displaying petrographic features that are distinct from those of type 1 and type 2 carbonates commonly observed in CM2 meteorites. These include carbonates interstitial to octahedral magnetite crystals, for which a new designation of \u201ctype 1c\u201d is suggested. The O isotopic values of dolomite (\u03b418O ranging from +21.1 to +25.8\u2030 and \u039417O from \u22124.9 to \u22124.0\u2030) are similar to those measured in dolomites from other CM chondrites. The presence of complex carbonates with a CaCO3 core and Mg\u2010enriched rim implies several generations of fluids and\/or their evolving composition on the CM parent body(ies). Petrographic characteristics indicate at least six stages of potentially overlapping carbonate and phyllosilicate formation events. We show that type 1 and type 2 calcite have distinct Raman spectral characteristics. Type 1 calcite is characterized by very broad peaks, whereas type 2 calcite displays narrow peaks similar to those of typical abiotic terrestrial calcite, suggesting high crystallinity. A carbonate Raman spectrum showing features characteristic of both aragonite and calcite likely documents an aragonite\u2010calcite phase transition. Raman spectroscopy also reveals the presence of organic matter in the majority of carbonates. This indicates that organic carbon was mobilized by aqueous fluids for extended periods.&#8221;<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Stefan Farsang, Ian A. Franchi, Xuchao Zhao, Timothy D. Raub, Simon A.T. Redfern, Monica M. Grady Meteoritics &amp; Planetary ScienceVersion of Record online: 01 May 2021 LINK (OPEN ACCESS)PDF (OPEN ACCESS) &#8220;The paragenesis of carbonates&#8230;<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[9,18],"tags":[3273,701,105,3646,1054],"_links":{"self":[{"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/27632"}],"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=27632"}],"version-history":[{"count":1,"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/27632\/revisions"}],"predecessor-version":[{"id":27633,"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/27632\/revisions\/27633"}],"wp:attachment":[{"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=27632"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=27632"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=27632"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}