{"id":1339,"date":"2016-05-28T18:00:43","date_gmt":"2016-05-28T09:00:43","guid":{"rendered":"http:\/\/geohiruzen.co.jp\/?p=1339"},"modified":"2019-08-27T19:09:59","modified_gmt":"2019-08-27T10:09:59","slug":"detrital-zircon-geochronology-of-sandstones-from-jurassic-and-cretaceous-accretionary-complexes-in-the-kanto-mountains-japan-implications-for-arc-provenance","status":"publish","type":"post","link":"https:\/\/geohiruzen.co.jp\/?p=1339","title":{"rendered":"Detrital zircon geochronology of sandstones from Jurassic and Cretaceous accretionary complexes in the Kanto Mountains, Japan: implications for arc provenance"},"content":{"rendered":"<div id=\"pubconte\">\n<h3 class=\"e_titile\">Detrital zircon geochronology of sandstones from Jurassic and Cretaceous accretionary complexes in the Kanto Mountains, Japan: implications for arc provenance<\/h3>\n<h4 class=\"storytitle\">Kazumasa Aoki\u30fbYukio Isozaki\u30fbShuhei Sakata\u30fbTomohiko Sato\u30fbShinji Yamamoto\u30fbTakafumi Hirata<\/h4>\n<p><a href=\"https:\/\/geohiruzen.co.jp\/wordpress\/egj05\/egj05_004.pdf\" target=\"_blank\" rel=\"noopener noreferrer\"><img decoding=\"async\" src=\"https:\/\/geohiruzen.co.jp\/wordpress\/egj05\/egj05_004.png\"><\/a><br \/>\nIn order to obtain information about provenance of terrigenous clastics that make up most\u3000of the Jurassic-Cretaceous accretionary complex (AC) of SW Japan, we have conducted detrital zircon\u3000U-Pb dating (laser-ablation inductively coupled plasma-mass spectrometry &#8211; LA-ICP-MS) of two Jurassic\u3000sandstones and four Cretaceous sandstones from the Mitsumine area, Kanto Mountains near Tokyo.<br \/>\nExcept for one sample, the youngest U-Pb age data obtained from each sample are 159.6 \u00b1 4.9, 122.7 \u00b1\u30003.8, 97.5 \u00b1 2.3, 96.7 \u00b1 4.3 and 87.7 \u00b1 1.9 Ma that are consistent with microfossil ages previously\u3000reported\u3000from shales in the same units, confirming the polarity of tectonic-downward growth of the ACs across\u3000the Butsuzo Tectonic Line, previously estimated from biostratigraphic dating. The new zircon U-Pb age\u3000data also reveal that the Jurassic and Cretaceous sandstones contain many ca. 200-160 Ma and ca. 120-90\u3000Ma detrital zircons, respectively. These results indicate that granitic arc-batholiths corresponding to each\u3000age were widely exposed in the fore-arc region when the sandstones were deposited. Detrital zircon data\u3000including this study have revealed that the Late Jurassic and Cretaceous sandstones are significantly low\u3000in population of Proterozoic ages than the Middle Jurassic sandstone, suggesting that a major provenance\u3000shift occurred between middle and late Jurassic. Arc batholith formation derived from oceanic-plate\u3000subduction typically causes high topographic relief in a fore-arc. Thus, it is likely that the formation of\u3000the granitic batholiths played an important role in the provenance shift, which had an important effect on\u3000the supply of terrigenous clastics in the Jurassic-Cretaceous fore-arcs in Japan. The large amount of Late\u3000Jurassic and Cretaceous batholiths might\u3000serve as barriers to restrict the supply route of the terrigenous\u3000clastics from the back-arc side.<\/p>\n<\/div>\n<p class=\"clear\" style=\"margin-left:60px\">\n\u25b3\u30af\u30ea\u30c3\u30af\u3059\u308b\u3068PDF\u30d5\u30a1\u30a4\u30eb\u3092\u8868\u793a\u3067\u304d\u307e\u3059<\/p>\n<div class=\"navlinks\">\n<a href=\"https:\/\/geohiruzen.co.jp\/wordpress\/?cat=24\"><img decoding=\"async\" src=\"https:\/\/geohiruzen.co.jp\/wordpress\/wp-content\/themes\/corporate\/images\/backtotopicon.gif\" alt=\"Back to index\">\u76ee\u6b21\u306b\u623b\u308b<\/a><\/p>\n<\/div>\n","protected":false},"excerpt":{"rendered":"<p>Detrital zircon geochronology of sandstones from Jurassic and Cretaceous accretionary complexes in the Kanto M &hellip; <\/p>\n<p class=\"link-more\"><a href=\"https:\/\/geohiruzen.co.jp\/?p=1339\" class=\"more-link\"><span class=\"screen-reader-text\">&#8220;Detrital zircon geochronology of sandstones from Jurassic and Cretaceous accretionary complexes in the Kanto Mountains, Japan: implications for arc provenance&#8221; \u306e<\/span>\u7d9a\u304d\u3092\u8aad\u3080<\/a><\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[25],"tags":[],"class_list":["post-1339","post","type-post","status-publish","format-standard","hentry","category-chigi005a"],"_links":{"self":[{"href":"https:\/\/geohiruzen.co.jp\/index.php?rest_route=\/wp\/v2\/posts\/1339","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/geohiruzen.co.jp\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/geohiruzen.co.jp\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/geohiruzen.co.jp\/index.php?rest_route=\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/geohiruzen.co.jp\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=1339"}],"version-history":[{"count":5,"href":"https:\/\/geohiruzen.co.jp\/index.php?rest_route=\/wp\/v2\/posts\/1339\/revisions"}],"predecessor-version":[{"id":2489,"href":"https:\/\/geohiruzen.co.jp\/index.php?rest_route=\/wp\/v2\/posts\/1339\/revisions\/2489"}],"wp:attachment":[{"href":"https:\/\/geohiruzen.co.jp\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=1339"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/geohiruzen.co.jp\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=1339"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/geohiruzen.co.jp\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=1339"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}