https://scholars.lib.ntu.edu.tw/handle/123456789/571678
標題: | First mid-ocean ridge-type ophiolite from the Meso-Tethys suture zone in the north-central Tibetan plateau | 作者: | Tang Y Zhai Q.-G Chung S.-L Hu P.-Y Wang J Xiao X.-C Song B Wang H.-T Lee H.-Y. SUN-LIN CHUNG |
關鍵字: | Basalt; Binary alloys; Cobalt; Geochronology; Lead alloys; Silicate minerals; Submarine geology; Trace elements; Uranium alloys; Zircon; Bangong-Nujiang Suture; Central Tibetan plateau; Geochemical composition; Mid ocean ridge basalts; Oceanic subduction; Serpentinized peridotites; Trace element patterns; Zircon U-Pb dating; Oceanography; age determination; basin evolution; Gondwana; mid-ocean ridge; ocean basin; ophiolite; petrogenesis; petrology; suture zone; Tethys; uranium-lead dating; zircon; China; Qinghai-Xizang Plateau | 公開日期: | 2020 | 卷: | 132 | 期: | 9-10 | 起(迄)頁: | 2202-2220 | 來源出版物: | Bulletin of the Geological Society of America | 摘要: | The Meso-Tethys was a late Paleozoic to Mesozoic ocean basin between the Cimmerian continent and Gondwana. Part of its relicts is exposed in the Bangong-Nujiang suture zone, in the north-central Tibetan Plateau, that played a key role in the evolution of the Tibetan plateau before the India-Asia collision. A Penrose-type ophiolitic sequence was newly discovered in the Ren Co area in the middle of the Bangong-Nujiang suture zone, which comprises serpentinized peridotites, layered and isotropic gabbros, sheeted dikes, pillow and massive basalts, and red cherts. Zircon U-Pb dating of gabbros and plagiogranites yielded 206Pb/238U ages of 169-147 Ma, constraining the timing of formation of the Ren Co ophiolite. The mafic rocks (i.e., basalt, diabase, and gabbro) in the ophiolite have uniform geochemical compositions, coupled with normal mid-ocean ridge basalt-type trace element patterns. Moreover, the samples have positive whole-rock εNd(t) [+9.2 to +8.3], zircon εHf(t) [+17 to +13], and mantle-like σ18O (5.8-4.3?) values. These features suggest that the Ren Co ophiolite is typical of mid-ocean ridge-type ophiolite that is identified for the first time in the Bangong-Nujiang suture zone. We argue that the Ren Co ophiolite is the relic of a fast-spreading ridge that occurred in the main oceanic basin of the Bangong-Nujiang segment of Meso- Tethys. Here the Meso-Tethyan orogeny involves a continuous history of oceanic subduction, accretion, and continental assembly from the Early Jurassic to Early Cretaceous. ? 2019 Geological Society of America. |
URI: | https://www.scopus.com/inward/record.uri?eid=2-s2.0-85086431082&doi=10.1130%2fB35500.1&partnerID=40&md5=d399badf67ef03870ad58cbc49801acc https://scholars.lib.ntu.edu.tw/handle/123456789/571678 |
ISSN: | 167606 | DOI: | 10.1130/B35500.1 |
顯示於: | 地質科學系 |
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