{"id":21265,"date":"2020-01-21T19:43:01","date_gmt":"2020-01-21T18:43:01","guid":{"rendered":"http:\/\/karmaka.de\/?p=21265"},"modified":"2020-01-21T19:43:03","modified_gmt":"2020-01-21T18:43:03","slug":"precise-radiometric-age-establishes-yarrabubba-western-australia-as-earths-oldest-recognised-meteorite-impact-structure","status":"publish","type":"post","link":"https:\/\/karmaka.de\/?p=21265","title":{"rendered":"Precise radiometric age establishes Yarrabubba, Western Australia, as Earth\u2019s oldest recognised meteorite impact structure<span class=\"badge-status\" style=\"background:#787878\">OPEN ACCESS<\/span>&nbsp;"},"content":{"rendered":"\n<p>Timmons M. Erickson, Christopher L. Kirkland, Nicholas E. Timms, Aaron J. Cavosie &amp; Thomas M. Davison<\/p>\n\n\n\n<p>Nature Communications 11 , 1\u20138<\/p>\n\n\n\n<p><a href=\"https:\/\/www.nature.com\/articles\/s41467-019-13985-7\" target=\"_blank\" rel=\"noreferrer noopener\"><strong>LINK (OPEN ACCESS)<\/strong><\/a><br>\n<a href=\"https:\/\/www.nature.com\/articles\/s41467-019-13985-7.pdf\" target=\"_blank\" rel=\"noreferrer noopener\"><strong>PDF (OPEN ACCESS)<\/strong><\/a><\/p>\n\n\n\n<p class=\"justify-text\">&#8220;The ~70 km-diameter Yarrabubba impact structure in Western Australia is regarded as among Earth\u2019s oldest, but has hitherto lacked precise age constraints. Here we present U\u2013Pb ages for impact-driven shock-recrystallised accessory minerals. Shock-recrystallised monazite yields a precise impact age of 2229\u2009\u00b1\u20095\u2009Ma, coeval with shock-reset zircon. This result establishes Yarrabubba as the oldest recognised meteorite impact structure on Earth, extending the terrestrial cratering record back\u2009&gt;200 million years. The age of Yarrabubba coincides, within uncertainty, with temporal constraint for the youngest Palaeoproterozoic glacial deposits, the Rietfontein diamictite in South Africa. Numerical impact simulations indicate that a 70 km-diameter crater into a continental glacier could release between 8.7\u2009\u00d7\u20091013 to 5.0\u2009\u00d7\u20091015 kg of H2O vapour instantaneously into the atmosphere. These results provide new estimates of impact-produced H2O vapour abundances for models investigating termination of the Paleoproterozoic glaciations, and highlight the possible role of impact cratering in modifying Earth\u2019s climate.&#8221; <\/p>\n","protected":false},"excerpt":{"rendered":"<p>Timmons M. Erickson, Christopher L. Kirkland, Nicholas E. Timms, Aaron J. Cavosie &amp; Thomas M. Davison Nature Communications 11 , 1\u20138 LINK (OPEN ACCESS) PDF (OPEN ACCESS) &#8220;The ~70 km-diameter Yarrabubba impact structure in Western&#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],"tags":[92,984,664,5390],"_links":{"self":[{"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/21265"}],"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=21265"}],"version-history":[{"count":1,"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/21265\/revisions"}],"predecessor-version":[{"id":21266,"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/21265\/revisions\/21266"}],"wp:attachment":[{"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=21265"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=21265"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=21265"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}