{"id":42192,"date":"2026-07-17T10:24:12","date_gmt":"2026-07-17T08:24:12","guid":{"rendered":"https:\/\/karmaka.de\/?p=42192"},"modified":"2026-07-17T10:24:13","modified_gmt":"2026-07-17T08:24:13","slug":"the-40k-k-dating-system-1-improving-data-interpretation-using-new-model-calculations","status":"publish","type":"post","link":"https:\/\/karmaka.de\/?p=42192","title":{"rendered":"The 40K-K dating system: 1. Improving data interpretation using new model calculations<span class=\"badge-status\" style=\"background:#787878\">OPEN ACCESS<\/span>&nbsp;"},"content":{"rendered":"\n<p>Farshid Nozarian, Suzette Timmerman, Ingo Leya<\/p>\n\n\n\n<p>MAPS, Version of Record online: 16 July 2026<\/p>\n\n\n\n<p><a href=\"https:\/\/onlinelibrary.wiley.com\/doi\/10.1111\/maps.70201\" target=\"_blank\" rel=\"noreferrer noopener\"><strong>LINK (OPEN ACCESS)<\/strong><\/a><br><a href=\"https:\/\/onlinelibrary.wiley.com\/doi\/epdf\/10.1111\/maps.70201\" target=\"_blank\" rel=\"noreferrer noopener\"><strong>PDF (OPEN ACCESS)<\/strong><\/a><\/p>\n\n\n\n<p class=\"justify-text\">&#8220;The 40K-K cosmic-ray exposure (CRE) dating system offers a promising method for determining exposure ages of iron meteorites by combining the radioactive cosmogenic 40K with the stable cosmogenic isotopes 39K and 41K. However, earlier applications relied on semi-empirical production models and inconsistent analytical data sets, limiting their reliability. This study presents a comprehensive reassessment of the 40K-K and 4He\/21Ne system using state-of-the-art model calculations. Production rates of 39K, 40K, and 41K were simulated with the GEANT4\u2013INCL++6 framework, incorporating updated excitation functions and fully considering depth-dependent shielding effects. The resulting model yields physically robust relationships between K isotopes and noble gas shielding proxies, such as 4He\/21Ne. In addition to revisiting the classical approach used by Voshage and co-workers, we introduce two new alternative strategies for calculating CRE ages: a two-component mixing model and a native-K correction approach that mitigates contamination effects. Overall, these developments establish a more accurate and physically consistent framework for future applications of the 40K\u2013K system in cosmochemistry and studies of galactic cosmic rays.&#8221;<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Farshid Nozarian, Suzette Timmerman, Ingo Leya MAPS, Version of Record online: 16 July 2026 LINK (OPEN ACCESS)PDF (OPEN ACCESS) &#8220;The 40K-K cosmic-ray exposure (CRE) dating system offers a promising method for determining exposure ages of&#8230;<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1598,69,214,68],"tags":[470,2816,7270,6654,6537,6785,7271,227,1849,2368,1341,1848],"_links":{"self":[{"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/42192"}],"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=42192"}],"version-history":[{"count":1,"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/42192\/revisions"}],"predecessor-version":[{"id":42193,"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/42192\/revisions\/42193"}],"wp:attachment":[{"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=42192"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=42192"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=42192"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}