{"id":34306,"date":"2023-09-24T11:18:40","date_gmt":"2023-09-24T09:18:40","guid":{"rendered":"https:\/\/karmaka.de\/?p=34306"},"modified":"2023-09-24T11:18:41","modified_gmt":"2023-09-24T09:18:41","slug":"the-chondritic-impactor-origin-of-the-ni-rich-component-in-australasian-tektites-and-microtektites","status":"publish","type":"post","link":"https:\/\/karmaka.de\/?p=34306","title":{"rendered":"The chondritic impactor origin of the Ni-rich component in Australasian tektites and microtektites<span class=\"badge-status\" style=\"background:#787878\">OPEN ACCESS<\/span>&nbsp;"},"content":{"rendered":"\n<p>L. Folco, P. Rochette, M. D&#8217;Orazio, M. Masotta<\/p>\n\n\n\n<p>Geochimica et Cosmochimica Acta<br>In Press, Journal Pre-proof, Available online 23 September 2023<\/p>\n\n\n\n<p><a href=\"https:\/\/www.sciencedirect.com\/science\/article\/pii\/S001670372300457X\" target=\"_blank\" rel=\"noreferrer noopener\"><strong>LINK (OPEN ACCESS)<\/strong><\/a><\/p>\n\n\n\n<p class=\"justify-text\">&#8220;In the Earth\u2019s crust, Ni is generally concentrated in mafic and ultramafic rocks and is coupled with Mg in Mg-olivine, Mg-pyroxene and spinel. Whether the Ni-rich, and in general, the mafic component of Australasian tektites and microtektites is terrestrial or meteoritic is still debated. To test the origin of the Ni-rich component, we studied the Ni versus Mg distribution in a large geochemical database of Australasian tektites (n = 208) and microtektites (n = 238) from the literature. Nickel contents of up to 428 \u00b5g\/g in tektites and 678 \u00b5g\/g in microtektites covary with Mg in tektites and in most (\u223c85%) of the microtektites defining a mixing trend between crustal and chondritic values, thereby documenting the chondritic origin of the Ni-rich component in Australasian tektites\/microtektites. Mixing calculations indicate up to 4% and up to 6% by weight chondritic component in tektites and microtektites, respectively. A possible mafic component of terrestrial origin is observed in a minority of tektite and microtektite specimens. This finding is consistent with previous works suggesting a possible occurrence of a chondritic signature in high-Ni tektites, based on the study of highly siderophile elements and Os isotopes, and high-Ni microtektites, based on Ni, Co, and Cr ratios. The combined geochemical and isotopic analysis of high-Ni tektites and microtektites in collections worldwide may thus reveal the chondritic impactor type that generated one of the presumably largest impacts in the Cenozoic.&#8221;<\/p>\n","protected":false},"excerpt":{"rendered":"<p>L. Folco, P. Rochette, M. D&#8217;Orazio, M. Masotta Geochimica et Cosmochimica ActaIn Press, Journal Pre-proof, Available online 23 September 2023 LINK (OPEN ACCESS) &#8220;In the Earth\u2019s crust, Ni is generally concentrated in mafic and ultramafic&#8230;<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[90,3296],"tags":[4141,2888,2343,3332,1955],"_links":{"self":[{"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/34306"}],"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=34306"}],"version-history":[{"count":1,"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/34306\/revisions"}],"predecessor-version":[{"id":34307,"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/34306\/revisions\/34307"}],"wp:attachment":[{"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=34306"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=34306"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=34306"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}