The search for ultrahigh-pressure metamorphic bodies and analysis of their structures in the Himalayas and the Japanese islands

喜马拉雅变质带地质调查和岩石学研究揭示了喜马拉雅变质带(HMB)的构造格局。超高压变质单元(包括含柯石英岩石)被常压、常温条件下的变质单元覆盖和覆盖。2004年，该基金配备了“聚焦图像集成系统”，用于本研究的所有显微观察，通过显微岩相学观察发现，在超高压榴辉岩中出现了罕见的锆石。榴辉岩的地球化学和年代学研究表明，榴辉岩的成因与三代玄武岩火山活动有关(锆石U-Pb年龄分别为267 Ma、180.2 Ma和114 Ma)。罗布萨蛇绿岩是…的主要组成部分。藏南(喜马拉雅以北)罗布萨蛇绿岩多为地幔橄榄岩，含金刚石等超高压指示矿物。已有的地质资料结合显微岩相学观察表明，罗布萨蛇绿岩整体上形成了倾倒的叠瓦状构造。北海道中部南部的霍罗曼橄榄岩岩体研究认为，在日达卡碰撞带的形成过程中，该岩体从地幔中分离出来。预计在橄榄岩体内附近存在高压和高温变质岩。在橄榄岩体内和周围进行了地质调查。在橄榄体的东北侧、南侧和东侧，确定了橄榄岩和片麻岩的边界，并分析了沿边界的变形构造。在橄榄岩西侧的两个位置发现了橄榄岩与沉积岩的边界，并分析了沿边界的变形构造。结合定向样品的微构造分析，结果表明，霍罗曼橄榄岩岩体自东向西逆冲于沉积岩之上。较少

<Study of the Himalayan metamorphic belt>The geological survey and petrological study of the western part of the Himalayas reveals the tectonic setup of the Himalayan metamorphic belt (HMB). The ultrahigh-pressure metamorphic unit (including coesite-bearing rocks) is overlain and underlain by metamorphic units of common pressure-temperature conditions. Microscopic petrographical observations with "In-focus image integration system", which was equipped by this grant in 2004 and used for all microscopic observations in this study, reveal unusual occurrence of zircon in ultrahigh-pressure eclogite. The geochemical and geochronological studies of eclogites (under the Visiting Research Program of the Institute for Study of the Earth's Interior, Okayama University at Misasa) suggest that the origin of eclogites can be correlated with three generations of basaltic volcanic activity (zircon U-Pb ages of c. 267 Ma, c. 180.2 Ma and c. 114 Ma).<Study of the Luobusa ophiolite>The major part of the … More Luobusa ophiolite in the southern Tibet (north of the Himalayas) is mantle peridotite which includes ultrahigh-pressure indicating minerals such as diamond. The existing geological data combined with microscopic petrographical Dbservations reveal that the Luobusa ophiolite as a whole forms overturned imbricate structure.<Study of the Horoman peridotite body>The Horoman peridotite body in the southern part of central Hokkaido has been considered to be separated from the mantle during the formation of the Hidaka collision belt. Presence of high-pressure and high-temperature metamorphic rocks is expected in the vicinity of the peridotite body. Geological survey was carried out in and around the peridotite body. In the northeast, south and east sides of the peridotite body, the boundaries between peridotites and gneisses were located and deformation structures along the boundaries were analyzed. The boundaries between peridotites and sedimentary rocks were found at two locations in the western side of the peridotite body and deformation structures along the boundaries were analyzed. The results combined with microtectonic analysis of oriented samples suggest that the Horoman peridotite body thrust over the sedimentary rocks from the east to the west. Less