LINK<\/strong><\/a><\/p>\n“We report mass-dependent and mass-independent Ca isotopic variations in nine chondrites from three groups: carbonaceous, ordinary and enstatite chondrites. There is about 0.25\u2030 per amu, i.e., \u223c1\u2030 in 44Ca\/40Ca, variation in chondrites: carbonaceous chondrites have the lightest Ca isotopes, enstatite chondrites have modeled bulk Earth like Ca isotopes, and ordinary chondrites are in between. The correlations between mass-dependent Ca isotopic variation and chemical variations in chondrites may reflect variable contributions from different endmembers, including refractory inclusions, in different chondrite groups. In detail, enstatite chondrites and the Earth share similar isotopic characteristics, but are very different in chemical compositions.<\/p>\n
At the \u00b11 and \u00b12 \u03b5-unit levels, respectively, there is no measurable 40Ca or 43Ca anomaly in bulk chondrites. Carbonaceous chondrites show several \u03b5-units of 48Ca excess. That is, Ca exhibits both mass-dependent and mass-independent isotopic variations in chondrites, similar to O isotopes. The 48Ca anomaly in bulk chondrites is positively correlated with 50Ti anomaly, but does not form simple correlation with 54Cr anomaly, implying multiple supernova sources for these neutron-rich isotopes in the Solar System. Finally, all meteorites with negative \u039417O have either 48Ca deficits (differentiated meteorites) or 48Ca excess (carbonaceous chondrites), implying that the Sun with a very negative \u039417O is probably also characterized by 48Ca anomaly compared to the Earth. CAIs cannot be taken as representative of the initial isotopic compositions of refractory elements like Ca for the Earth-Moon system.”<\/p>\n","protected":false},"excerpt":{"rendered":"
Shichun Huang, Stein B. Jacobsen Geochimica et Cosmochimica Acta In Press, Accepted Manuscript, Available online 4 October 2016 http:\/\/dx.doi.org\/10.1016\/j.gca.2016.09.039 LINK “We report mass-dependent and mass-independent Ca isotopic variations in nine chondrites from three groups: carbonaceous,…<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[9,17,7],"tags":[3306,3307,106,3273,1813,1807],"_links":{"self":[{"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/10107"}],"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=10107"}],"version-history":[{"count":2,"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/10107\/revisions"}],"predecessor-version":[{"id":10109,"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/10107\/revisions\/10109"}],"wp:attachment":[{"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=10107"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=10107"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=10107"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}