LINK<\/strong><\/a><\/p>\n\n\n\n“We describe an ultrarefractory Ca,Al-rich inclusion (UR CAI) CC072\u20131 in the ordinary H3 chondrite Chug Chug 072 (CC 072), which is a polymict microbrecia containing carbonaceous chondrite clasts. CC072\u20131 consists of several mineralogically-zoned nodules. The cores of nodules, composed of perovskite, warkite, and kangite, are surrounded by mantles of Sc-rich davisite and spinel. The texture and mineralogical zoning of CC072\u20131 suggest it formed by gas-solid condensation in a cooling nebular gas. Most primary minerals of CC072\u20131 are enriched in FeO, indicative of metasomatic alteration and thermal metamorphism in an asteroidal setting. The CAI is isotopically heterogeneous: spinel is 16O-rich (\u039417O\u202f~\u202f\u221223 \u2030, where \u039417O\u202f=\u202f\u03b417O \u2013 0.52\u202f\u00d7\u202f\u03b418O), whereas warkite, perovskite, and davisite are 16O-depleted to various degrees (\u039417O ranges from ~ \u221218 to \u22123 \u2030). We concluded that CC072\u20131 likely originated in a 16O-rich gas of approximately solar composition, and subsequently experienced post-crystallization O-isotope exchange with an aqueous fluid. Since \u039417O of aqueous fluid in type 3 ordinary chondrites inferred from \u039417O of secondary magnetite and fayalite is ~ +5 \u2030, significantly higher than the \u039417O of 16O-depleted minerals in CC072\u20131, the oxygen-isotope exchange experienced by CC072\u20131 could have occurred prior to its incorporation into the CC072 parent asteroid, possibly in a CM-like chondrite parent body. Following the migration, accretion and low-velocity impact event the UR CAI was incorporated in the H3 chondrite during brecciation.”<\/p>\n","protected":false},"excerpt":{"rendered":"
Konstantin M. Ryazantsev , Marina A. Ivanova, Alexander N. Krot, Kazu Nagashima, Cyril A. Lorenz, Vasiliy D. Shcherbakov Geochemistry, Available online 26 October 2026 LINK “We describe an ultrarefractory Ca,Al-rich inclusion (UR CAI) CC072\u20131 in…<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[66,55,3249,6,7,57],"tags":[1846,2927,7320,4852,1807,4373,5141],"class_list":["post-42703","post","type-post","status-publish","format-standard","hentry","category-cai","category-chondrite-components","category-clast","category-h","category-chondrite","category-refractory-inclusions","tag-cai","tag-carbonaceous-clasts","tag-chug-chug-072","tag-h-chondrite","tag-chondrite","tag-ultrarefractory-inclusion","tag-ur-cai"],"_links":{"self":[{"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/42703","targetHints":{"allow":["GET"]}}],"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=42703"}],"version-history":[{"count":1,"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/42703\/revisions"}],"predecessor-version":[{"id":42704,"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/42703\/revisions\/42704"}],"wp:attachment":[{"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=42703"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=42703"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=42703"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}