LINK<\/strong><\/a><\/p>\n“The initial 60Fe\/56Fe ratio of chondrules from unequilibrated ordinary chondrites (UOCs) can potentially help constrain the stellar source of short-lived radionuclides and develop the 60Fe-60Ni (t1\/2=2.6 Ma) system for early solar system chronology. However, progress with the 60Fe-60Ni system has been hindered by discrepancies between initial ratios inferred from bulk and in situ Fe-Ni analyses. Telus et al. (2016) show that discrepancies between these different techniques stem from late-stage open-system Fe-Ni mobilization. Here, we report in situ analyses of the Fe-Ni isotopic composition of ferromagnesian silicates in chondrules from UOCs using the ion microprobe. Of the 24 chondrules analyzed for this study, a few chondrules have clearly resolved excesses in 60Ni of up to 70\u2030; however, the correlations with the Fe\/Ni ratios are weak. Although complications from Fe-Ni redistribution make it difficult to interpret the data, we show that the initial 60Fe\/56Fe ratio for UOC chondrules is between 5\u00d710-8 and 3.0\u00d710-7. This is consistent with a late supernova source for 60Fe, but self-enrichment of the molecular cloud is another possible mechanism for incorporating 60Fe in the solar system. Discrepancies between bulk and in situ analyses remain, but likely stem from late-stage open-system Fe-Ni mobilization.”<\/p>\n","protected":false},"excerpt":{"rendered":"
Myriam Telus, Gary R. Huss, Kazuhide Nagashima, Ryan C. Ogliore, Shogo Tachibana Geochimica et Cosmochimica Acta In Press, Accepted Manuscript, Available online 12 June 2017 LINK “The initial 60Fe\/56Fe ratio of chondrules from unequilibrated ordinary…<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[56,72,7,71,2961],"tags":[445,400,3929,424,2634],"_links":{"self":[{"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/12801"}],"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=12801"}],"version-history":[{"count":1,"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/12801\/revisions"}],"predecessor-version":[{"id":12802,"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/12801\/revisions\/12802"}],"wp:attachment":[{"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=12801"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=12801"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=12801"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}