{"id":42403,"date":"2026-08-08T19:22:27","date_gmt":"2026-08-08T17:22:27","guid":{"rendered":"https:\/\/karmaka.de\/?p=42403"},"modified":"2026-08-08T23:30:26","modified_gmt":"2026-08-08T21:30:26","slug":"the-hydrogen-isotopic-composition-and-content-of-the-ureilite-parent-body-constraints-from-new-ungrouped-achondrites","status":"publish","type":"post","link":"https:\/\/karmaka.de\/?p=42403","title":{"rendered":"The hydrogen isotopic composition and content of the ureilite parent body: constraints from new ungrouped achondrites<span class=\"badge-status\" style=\"background:#787878\">OPEN ACCESS<\/span>&nbsp;"},"content":{"rendered":"\n<p>B.G. Rider-Stokes, A. Stephant, M. Nottingham, J. Gamblin, e. . F\u00fcri, S.S. Russell, X. Zhao, M. Anand, M.J. Whitehouse, M.M. Grady<\/p>\n\n\n\n<p>Geochimica et Cosmochimica Acta, In Press, Journal Pre-proof, Available online 8 August 2026<\/p>\n\n\n\n<p><a href=\"https:\/\/www.sciencedirect.com\/science\/article\/abs\/pii\/S0016703726005065\" target=\"_blank\" rel=\"noreferrer noopener\"><strong>LINK +  PDF (OPEN ACCESS)<\/strong><\/a><\/p>\n\n\n\n<p class=\"justify-text\">&#8220;Evidence for SiO2-rich melts on the ureilite parent body (UPB) stems from feldspathic clasts within polymict ureilites and has been additionally preserved and recorded in rare fragments of the Almahata Sitta meteorite suite, which originated from the asteroid 2008 TC3. These unique fragments demonstrated that ancient crust-forming volcanism on small planetary bodies was not simply restricted to basaltic lithologies. Two recent Northwest Africa finds (NWA) 15,820 and NWA 16789 expand the known quantity of SiO2-rich material from the UPB, allowing for a more representative investigation into the chemical and isotopic variations among these unique lithologies. Here, we measured the H abundance and isotopic composition (\u03b4D) of NWA 15820 and NWA 16789 to evaluate the bulk UPB water content, resulting in a revised minimum bulk water content of 13\u202f\u00b5g\/g H2O. Furthermore, we report the \u03b4D of water in the UPB. While the D\/H ratio of late-stage phosphates and glass is highly fractionated as a result of magmatic degassing, nominally anhydrous silicate pyroxene better records the original \u03b4D of the UPB. In particular, the pyroxene within NWA 16789 records a \u03b4D value of 83\u202f\u00b1\u202f79\u2030, which we infer is the best estimate for the original \u03b4D of water in the UPB.&#8221;<\/p>\n","protected":false},"excerpt":{"rendered":"<p>B.G. Rider-Stokes, A. Stephant, M. Nottingham, J. Gamblin, e. . F\u00fcri, S.S. Russell, X. Zhao, M. Anand, M.J. Whitehouse, M.M. Grady Geochimica et Cosmochimica Acta, In Press, Journal Pre-proof, Available online 8 August 2026 LINK&#8230;<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[28,53,507],"tags":[460,1837,1684,7155,7154,2285,245,1952,1088],"_links":{"self":[{"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/42403"}],"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=42403"}],"version-history":[{"count":2,"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/42403\/revisions"}],"predecessor-version":[{"id":42406,"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/42403\/revisions\/42406"}],"wp:attachment":[{"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=42403"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=42403"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=42403"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}