LINK<\/strong><\/a><\/p>\n\n\n\n“Highlights<\/p>\n\n\n\n
\u2022 We investigated a large, fine-grained micrometeorite TAM19B-7 from a water-rich C-type asteroid.
\u2022 TAM19B-7 has a 13C enriched bulk composition.
\u2022 The infrared spectra show a feature centered at 3.9\u202f\u03bcm typical of carbonates.
\u2022 Carbon composition indicates either open system gas loss during aqueous alteration or carbonate formation from isotopically heavy soluble organics.
\u2022 Carbonates have been detected on hydrated surfaces of Ceres, Bennu and Ryugu.”<\/p>\n\n\n\n
“Micrometeorites represent a major potential source of volatiles for the early Earth, although often overlooked due to their small sizes and the effects of atmospheric entry. In this study we explore an unusual ~2000\u202f\u03bcm, fine-grained unmelted micrometeorite TAM19B-7 derived from a water-rich C-type asteroid. Previous analysis revealed a unique O-isotope composition and intensely aqueously altered geological history. We investigated its carbon isotopic composition using the NanoSIMS and characterized the carbon-bearing carriers using Raman and Near-Infrared spectroscopy. We found that TAM19B-7 has a 13C enriched bulk composition (\u03b413C\u202f=\u202f+3\u202f\u00b1\u202f8 \u2030), including a domain with 13C depletion (\u03b413C\u202f=\u202f\u221227.1 \u2030). Furthermore, a few micro-scale domains show 13C enrichments (\u03b413C from +12.9 \u2030 to +32.7 \u2030) suggesting much of the particle\u2019s carbon content was reprocessed into fine-grained carbonates, likely calcite. The heavy bulk C-isotope composition of TAM19B-7 indicates either open system gas loss during aqueous alteration or carbonate formation from isotopically heavy soluble organics. Carbonates have been detected on small body surfaces, including across dwarf planet Ceres, and on the C-type asteroids Bennu and Ryugu. The preservation of both carbonates with 13C enrichments and organic carbon with 13C depletion in TAM19B-7, despite having been flash heated to high temperatures (<1000\u202f\u00b0C), demonstrates the importance of cosmic dust as a volatile reservoir.”<\/p>\n","protected":false},"excerpt":{"rendered":"
Victoria Froh, Maitrayee Bose, Martin D. Suttle, Jacopo Nava, Luigi Folco, Lynda B. Williams, Julie Castillo-Rogez IcarusIn Press, Journal Pre-proof, Available online 12 October 2022 LINK “Highlights \u2022 We investigated a large, fine-grained micrometeorite TAM19B-7…<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[77,2350,112],"tags":[1350,1854,3991,250,701,815,327,369],"_links":{"self":[{"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/31363"}],"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=31363"}],"version-history":[{"count":1,"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/31363\/revisions"}],"predecessor-version":[{"id":31364,"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/31363\/revisions\/31364"}],"wp:attachment":[{"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=31363"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=31363"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=31363"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}