{"id":28675,"date":"2021-09-01T16:44:37","date_gmt":"2021-09-01T14:44:37","guid":{"rendered":"https:\/\/karmaka.de\/?p=28675"},"modified":"2021-09-01T16:44:38","modified_gmt":"2021-09-01T14:44:38","slug":"quantitative-determination-of-the-shock-stage-of-l6-ordinary-chondrites-using-x-ray-diffraction","status":"publish","type":"post","link":"https:\/\/karmaka.de\/?p=28675","title":{"rendered":"Quantitative determination of the shock stage of L6 ordinary chondrites using X-ray diffraction"},"content":{"rendered":"\n<p>Naoya Imae, Makoto Kimura<\/p>\n\n\n\n<p>American Mineralogist<br>September 01, 2021, Vol.106, 1470-1479. doi:https:\/\/doi.org\/10.2138\/am-2021-7554<\/p>\n\n\n\n<p><a href=\"https:\/\/pubs.geoscienceworld.org\/msa\/ammin\/article-abstract\/106\/9\/1470\/607192\/Quantitative-determination-of-the-shock-stage-of\" target=\"_blank\" rel=\"noreferrer noopener\"><strong>LINK<\/strong><\/a><\/p>\n\n\n\n<p class=\"justify-text\">&#8220;The shock stages of 14 L6 ordinary chondrites are estimated using the random X-ray diffraction patterns of polished thin section samples and the in-plane rotation method. The mean lattice strains and grain size factors for olivine and orthopyroxene are determined from the analyses based on the Williamson\u2013Hall plots, which depict the tangent Bragg angle and integral breadth \u03b2. The lattice strain in olivine, eOl, is distributed from ~0.05% to ~0.25%, while that in orthopyroxene, eOpx, is distributed from ~0.1 to ~0.4%, where we selected the isolated peaks of olivine and orthopyroxene. The olivine peaks have Miller indices of (130), (211), (222), and (322), while the orthopyroxene peaks have Miller indices of (610), (511), (421), (631), and (12.1.2). The intercept for integral breadth \u03b2O10 and \u03b2Opx0 for the Williamson\u2013Hall plots correlates with the grain size of the constituent minerals. The grain size is proportional to the inverse of \u03b20 since the \u03b2 intercept increases with the shock stage. Introducing a new parameter, \u2013\u03b5\/log \u03b20 for olivine (0.04\u20130.16) and orthopyroxene (0.07\u20130.32) reveals a clear relationship between them: \u2013\u03b5Opx\/log \u03b2Opx0 = \u20130.01+ 2.0 (\u2013\u03b5Ol\/log \u03b2O10\u2060) (R &gt; 0.9). In addition, the isolated peak of plagioclase (201) systematically changes as the shock stage increases, suggesting the progress of amorphization (maskelynitization). Another parameter, (I\/FWHM)Pl(201) reveals additional relationships: \u2013\u03b5Ol\/log \u03b2O10 = 0.14(\u00b10.01) \u2212 5.2 \u00d7 10\u22125 (\u00b15.7 \u00d7 10\u22126) \u00d7 (I\/FWHM)Pl(201), and \u2013\u03b5Opx\/log \u03b2Opx0 = 0.25(\u00b10.04) \u2212 8.9 \u00d7 10\u22125 (\u00b12.6 \u00d7 10\u22125) \u00d7 10\u20135 \u00d7 (I\/FWHM)Pl(201). These three parameters systematically change with the shock stage, suggesting that they are suitable shock barometers. The present method is useful to evaluate the shock stage of L6 chondrites and potentially enables quantitative shock stage classification for stony meteorites.&#8221;<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Naoya Imae, Makoto Kimura American MineralogistSeptember 01, 2021, Vol.106, 1470-1479. doi:https:\/\/doi.org\/10.2138\/am-2021-7554 LINK &#8220;The shock stages of 14 L6 ordinary chondrites are estimated using the random X-ray diffraction patterns of polished thin section samples and 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":[1598,23,7,63],"tags":[3188,103,1807,1844,6094,2693],"_links":{"self":[{"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/28675"}],"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=28675"}],"version-history":[{"count":1,"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/28675\/revisions"}],"predecessor-version":[{"id":28676,"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/28675\/revisions\/28676"}],"wp:attachment":[{"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=28675"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=28675"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=28675"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}