{"id":34283,"date":"2023-09-19T15:14:52","date_gmt":"2023-09-19T13:14:52","guid":{"rendered":"https:\/\/karmaka.de\/?p=34283"},"modified":"2023-09-19T15:14:54","modified_gmt":"2023-09-19T13:14:54","slug":"sims-u-pb-dating-of-micro-zircons-in-the-lunar-meteorites-dhofar-1528-and-dhofar-1627","status":"publish","type":"post","link":"https:\/\/karmaka.de\/?p=34283","title":{"rendered":"SIMS U-Pb dating of micro-zircons in the lunar meteorites Dhofar 1528 and Dhofar 1627<span class=\"badge-status\" style=\"background:#787878\">OPEN ACCESS<\/span>&nbsp;"},"content":{"rendered":"\n<p>Bidong Zhang, Yangting Lin, Jialong Hao, Devin L. Schrader, Meenakshi Wadhwa, Randy L. Korotev, William K. Hartmann, Audrey Bouvier<\/p>\n\n\n\n<p>MAPS<br>Version of Record online: 19 September 2023<\/p>\n\n\n\n<p><a href=\"https:\/\/onlinelibrary.wiley.com\/doi\/10.1111\/maps.14078\" target=\"_blank\" rel=\"noreferrer noopener\"><strong>LINK (OPEN ACCESS)<\/strong><\/a><br><a href=\"https:\/\/onlinelibrary.wiley.com\/doi\/epdf\/10.1111\/maps.14078\" target=\"_blank\" rel=\"noreferrer noopener\"><strong>PDF (OPEN ACCESS)<\/strong><\/a><\/p>\n\n\n\n<p class=\"justify-text\">&#8220;About half of the lunar meteorites in our collections are feldspathic breccias. Acquiring geochronologic information from these breccias is challenging due to their low radioactive-element contents and their often polymict nature. We used high-spatial-resolution (5\u2009\u03bcm) NanoSIMS (nanoscale secondary ion mass spectrometry) U-Pb dating technique to date micro-zircons in the lunar feldspathic meteorites Dhofar 1528 and Dhofar 1627. Three NanoSIMS dating spots of two zircon grains from Dhofar 1528 show a discordia with an upper intercept at 4354\u2009\u00b1\u200976\u2009Ma and a lower intercept at 332\u2009\u00b1\u20091407\u2009Ma (2\u03c3, MSWD\u2009=\u20090.01, p\u2009=\u20090.91). Three spots of two zircon grains in Dhofar 1627 define a discordia with an upper intercept at 3948\u2009\u00b1\u200930\u2009Ma and a lower intercept at 691\u2009\u00b1\u2009831\u2009Ma (2\u03c3, MSWD\u2009=\u20090.40, p\u2009=\u20090.53). Both samples likely experienced shock metamorphism caused by impacts. Based on the clastic nature, lack of recrystallization and the consistent U-Pb and Pb-Pb dates of the zircons in Dhofar 1528, the U-Pb date of 4354\u2009Ma is interpreted as the crystallization age of its Mg-suite igneous precursor. Some of the Dhofar 1627 zircons show poikilitic texture, a crystallization from the matrix impact melt, so the U-Pb date of 3948\u2009Ma corresponds to an impact event, likely the Imbrium basin-forming event. These data are the first radiometric ages for these two meteorites and demonstrate that in situ (high spatial resolution) U-Pb dating has potential for extracting geochronological information about igneous activities and impact events from lunar feldspathic and polymict breccias.&#8221;<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Bidong Zhang, Yangting Lin, Jialong Hao, Devin L. Schrader, Meenakshi Wadhwa, Randy L. Korotev, William K. Hartmann, Audrey Bouvier MAPSVersion of Record online: 19 September 2023 LINK (OPEN ACCESS)PDF (OPEN ACCESS) &#8220;About half of the&#8230;<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[41,115],"tags":[4756,6549,1827,2238,6418,664,184],"_links":{"self":[{"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/34283"}],"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=34283"}],"version-history":[{"count":1,"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/34283\/revisions"}],"predecessor-version":[{"id":34284,"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/34283\/revisions\/34284"}],"wp:attachment":[{"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=34283"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=34283"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=34283"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}