{"id":21570,"date":"2020-02-24T20:03:26","date_gmt":"2020-02-24T19:03:26","guid":{"rendered":"http:\/\/karmaka.de\/?p=21570"},"modified":"2020-02-24T20:03:27","modified_gmt":"2020-02-24T19:03:27","slug":"formation-of-lunar-highlands-anorthosites","status":"publish","type":"post","link":"https:\/\/karmaka.de\/?p=21570","title":{"rendered":"Formation of lunar highlands anorthosites"},"content":{"rendered":"\n<p>Xiaoqing Xu, Hejiu Hui, Wei Chen, Shichun Huang, Clive R. Neal, Xisheng Xu<\/p>\n\n\n\n<p>Earth and Planetary Science Letters<br>\nVolume 536, 15 April 2020, 116138<\/p>\n\n\n\n<p><a href=\"https:\/\/www.sciencedirect.com\/science\/article\/abs\/pii\/S0012821X20300819\" target=\"_blank\" rel=\"noreferrer noopener\"><strong>LINK<\/strong><\/a><\/p>\n\n\n\n<p>&#8220;Highlights<\/p>\n\n\n\n<p>\u2022    We report major and trace element contents of plagioclase in meteoritic anorthosites.<br>\n\u2022    Simple LMO crystallization cannot derive REE contents in anorthositic plagioclase.<br>\n\u2022    Plagioclase and mafic minerals in lunar anorthosites may not be in equilibrium.<br>\n\u2022    Anorthosites are primordial crust metasomatized by KREEP and mantle-derived melts.&#8221;<\/p>\n\n\n\n<p class=\"justify-text\">&#8220;The lunar magma ocean (LMO) model was proposed after the discovery of anorthosite in Apollo 11 samples. However, the chemical and isotopic compositions of lunar anorthosites are not fully consistent with its LMO origin. We have analyzed major and trace elements in anorthositic clasts from ten lunar feldspathic meteorites, which are related to the solidification of the LMO. The plagioclase rare earth element (REE) abundances and patterns are not correlated with the Mg# of coexisting mafic minerals in anorthosites, implying that mafic minerals and plagioclase may not be in chemical equilibrium, consistent with their textural differences. The REE abundances in plagioclase range approximately fortyfold, which cannot be produced by fractional crystallization of a single magma. Combining plagioclase trace element data from Apollo and meteoritic anorthosites, we propose that plagioclases derived from the LMO floated to the surface to form the primordial crust, which then may have been metasomatized by incompatible-element-rich KREEP (potassium, rare earth element, phosphorus) melts and mantle-derived partial melts. The lunar anorthosites may represent this metasomatized crust rather than solely a derivative from the LMO. Furthermore, silicate melts similar to the metasomatic agents may also have melted the crust to form the Mg-suite rocks. This hypothesis is consistent with overlapping ranges of age and initial \u03b5Nd between lunar anorthosites and Mg-suite rocks. These events are consistent with an overturn event of the cumulate mantle very early after primordial crust formation to produce the partial melts that metasomatized the crust.&#8221;<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Xiaoqing Xu, Hejiu Hui, Wei Chen, Shichun Huang, Clive R. Neal, Xisheng Xu Earth and Planetary Science Letters Volume 536, 15 April 2020, 116138 LINK &#8220;Highlights \u2022 We report major and trace element contents 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":[41,115],"tags":[162,1827,4955,850,1857,334,779],"_links":{"self":[{"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/21570"}],"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=21570"}],"version-history":[{"count":1,"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/21570\/revisions"}],"predecessor-version":[{"id":21571,"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/21570\/revisions\/21571"}],"wp:attachment":[{"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=21570"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=21570"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=21570"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}