{"id":42588,"date":"2026-09-26T11:06:33","date_gmt":"2026-09-26T09:06:33","guid":{"rendered":"https:\/\/karmaka.de\/?p=42588"},"modified":"2026-09-26T11:08:20","modified_gmt":"2026-09-26T09:08:20","slug":"oxygen-isotope-thermometry-and-composition-of-aqueous-fluids-within-the-parent-body-of-asteroid-101955-bennu","status":"publish","type":"post","link":"https:\/\/karmaka.de\/?p=42588","title":{"rendered":"Oxygen isotope thermometry and composition of aqueous fluids within the parent body of asteroid (101955) Bennu<span class=\"badge-status\" style=\"background:#787878\">OPEN ACCESS<\/span>&nbsp;"},"content":{"rendered":"\n<p>Gary R. Huss, Kazuhide Nagashima, Elena Dobric\u0103, Alexander N. Krot, Gregory Cane, Zoe E. Wilbur, Timothy J. McCoy, Catherine M. Corrigan, Sara S. Russell, Jessica J. Barnes, Ann N. Nguyen, Harold C. Connolly Jr., Dante S. Lauretta<\/p>\n\n\n\n<p>MAPS, Version of Record online: 25 September 2026<\/p>\n\n\n\n<p><a href=\"https:\/\/onlinelibrary.wiley.com\/doi\/10.1111\/maps.70231\" target=\"_blank\" rel=\"noreferrer noopener\"><strong>LINK (OPEN ACCESS)<\/strong><\/a><br><a href=\"https:\/\/onlinelibrary.wiley.com\/doi\/epdf\/10.1111\/maps.70231\" target=\"_blank\" rel=\"noreferrer noopener\"><strong>PDF (OPEN ACCESS)<\/strong><\/a><\/p>\n\n\n\n<p class=\"justify-text\">We report on the petrography and oxygen isotopic compositions from in situ analyses of carbonates (Ca-carbonate, dolomite, and Fe-rich magnesite), magnetite, and apatite in particles from asteroid Bennu. Using oxygen isotope thermometry of Ca-carbonate, dolomite, and magnetite, we estimated crystallization temperatures and the oxygen isotopic compositions of the aqueous fluids from which they precipitated. The Ca-carbonate\u2013magnetite pairs formed at lower temperatures (\u22125 to 20\u00b0C) than the dolomite\u2013magnetite pairs (5\u201389\u00b0C); the uncertainties are \u00b110\u201316\u00b0C. The inferred fluid compositions for Ca-carbonate\u2013magnetite pairs are \u03b418O\u2009=\u20090.6\u2030\u20139\u2030 and \u039417O\u2009=\u20091.8\u2030\u20132.7\u2030, whereas for dolomite\u2013magnetite pairs, they are \u03b418O\u2009=\u2009\u22122.2\u2030 to 7.6\u2030 and \u039417O\u2009=\u2009\u22120.1\u2030 to 0.9\u2030. On a three-isotope oxygen diagram (\u03b417O vs. \u03b418O), 11 out of 13 of our inferred aqueous fluid compositions plot along a single line with a slope of ~0.8, potentially indicating precipitation from a single isotopically evolving fluid. Two dolomite\u2013magnetite pairs appear to be outliers and may have formed from fluids with different oxygen isotopic compositions. The oxygen isotope data presented herein overlap with those reported from samples of asteroid Ryugu, supporting a possible close genetic relationship between these asteroids.&#8221;<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Gary R. Huss, Kazuhide Nagashima, Elena Dobric\u0103, Alexander N. Krot, Gregory Cane, Zoe E. Wilbur, Timothy J. McCoy, Catherine M. Corrigan, Sara S. Russell, Jessica J. Barnes, Ann N. Nguyen, Harold C. Connolly Jr., Dante&#8230;<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[77,552,65],"tags":[5719,4844,1845,4349],"_links":{"self":[{"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/42588"}],"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=42588"}],"version-history":[{"count":2,"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/42588\/revisions"}],"predecessor-version":[{"id":42591,"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/42588\/revisions\/42591"}],"wp:attachment":[{"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=42588"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=42588"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=42588"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}