{"id":20656,"date":"2019-11-04T17:58:18","date_gmt":"2019-11-04T16:58:18","guid":{"rendered":"http:\/\/karmaka.de\/?p=20656"},"modified":"2019-11-04T17:58:19","modified_gmt":"2019-11-04T16:58:19","slug":"discovery-of-nanophase-iron-particles-and-high-pressure-clinoenstatite-in-a-heavily-shocked-ordinary-chondrite-implications-for-the-decomposition-of-pyroxene","status":"publish","type":"post","link":"https:\/\/karmaka.de\/?p=20656","title":{"rendered":"Discovery of nanophase iron particles and high pressure clinoenstatite in a heavily shocked ordinary chondrite: implications for the decomposition of pyroxene"},"content":{"rendered":"\n<p>Zhuang Guo, Yang Li, Shen Liu, Huifang Xu, Shijie Li, Xiongyao Li, Yangting Lin, Ian M.Coulson, Mingming Zhang<\/p>\n\n\n\n<p>Geochimica et Cosmochimica Acta<br>\nIn Press, Journal Pre-proof, Available online 4 November 2019<\/p>\n\n\n\n<p><a href=\"https:\/\/www.sciencedirect.com\/science\/article\/pii\/S0016703719306908\" target=\"_blank\" rel=\"noreferrer noopener\"><strong>LINK<\/strong><\/a><\/p>\n\n\n\n<p class=\"justify-text\">&#8220;Although pure metallic iron (i.e. that with an Fe content of greater than 99%) commonly occurs in achondrites, and within the returned soil from asteroids or the Lunar surface, it is rarely found in ordinary chondrites meteorites. Abundant nanophase iron particles (np-Fe0) were identified in pyroxene glass, within the shock melt vein of Grove Mountains (GRV) 022115, which is an ordinary (L6) chondrite, with a shock stage determined as S5. The association of np-Fe0, highly defective high pressure clinoenstatite (HP-CEn), silica glass, as well as vesicles, embedded in a pyroxene glass selvage within the shock melt vein in this meteorite suggests that these phases formed as the result of decomposition of the host pyroxene grain, a process induced by the shock event that affected GRV 022115. The reaction to account for this mineral breakdown can be written as: FeSiO3 \u2192Fe + SiO2 + 1\/2O2 \u2191 (MgSiO3 remain in the HP-CEn). The pressure and temperature condition attending this reaction are estimated at 20-23 GPa and over 1800 \u2103, as indicated by the surrounded high-pressure mineral assemblage: ringwoodite, majorite, and magnesiow\u00fcstite. This study provides evidence to the formation of np-Fe0 derived from pyroxene, and HP-CEn quenched metastably in such shocked vein could preserve the metastable phase transitions history record.&#8221;<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Zhuang Guo, Yang Li, Shen Liu, Huifang Xu, Shijie Li, Xiongyao Li, Yangting Lin, Ian M.Coulson, Mingming Zhang Geochimica et Cosmochimica Acta In Press, Journal Pre-proof, Available online 4 November 2019 LINK &#8220;Although pure metallic&#8230;<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[23,7,63],"tags":[5255,5253,3188,5254,1807,644,1844],"_links":{"self":[{"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/20656"}],"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=20656"}],"version-history":[{"count":1,"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/20656\/revisions"}],"predecessor-version":[{"id":20657,"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/20656\/revisions\/20657"}],"wp:attachment":[{"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=20656"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=20656"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=20656"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}