https://scholars.lib.ntu.edu.tw/handle/123456789/571682
標題: | Closure of the Bangong-Nujiang Tethyan Ocean in the central Tibet: Results from the provenance of the Duoni formation | 作者: | Zhu Z Zhai Q Hu P Chung S Tang Y Wang H Wu H Wang W Huang Z Lee H. SUN-LIN CHUNG |
關鍵字: | Binary alloys; Chromite; Lead alloys; Sandstone; Silicate minerals; Uranium alloys; Zircon; Bangong-Nujiang Suture; Duoni Formation; Early Cretaceous; Late cretaceous; Ophiolite complex; Qiangtang terrane; Tectonic history; Tibetan Plateau; Igneous rocks; depositional environment; fluvial deposit; ophiolite; provenance; sandstone; suture zone; tectonic evolution; uranium-lead dating; zircon; Bangong Co-Nujiang Suture Zone; China; Qinghai-Xizang Plateau; Xizang | 公開日期: | 2019 | 卷: | 89 | 期: | 10 | 起(迄)頁: | 1039-1054 | 來源出版物: | Journal of Sedimentary Research | 摘要: | The closure of the Bangong-Nujiang Tethyan Ocean (BNTO) and consequent Lhasa-Qiangtang collision is vital to reasonably understanding the early tectonic history of the Tibetan Plateau before the India-Eurasia collision. The timing of the Lhasa-Qiangtang collision was mainly constrained by the ophiolite and magmatic rocks in previous studies, with only limited constraints from the sedimentary rocks within and adjacent to the Bangong-Nujiang suture zone. In the middle segment of the Bangong-Nujiang suture zone, the Duoni Formation, consisting of a fluvial delta sequence with minor andesite interlayers, was originally defined as the Late Cretaceous Jingzhushan Formation and interpreted as the products of the Lhasa-Qiangtang collision during the Late Cretaceous. Our new zircon U-Pb data from two samples of andesite interlayers demonstrate that it was deposited during the latest Early Cretaceous (ca. 113 Ma) rather than Late Cretaceous. Systemic studies on the sandstone detrital model, heavy-mineral assemblage, and clasts of conglomerate demonstrate a mixed source of both Lhasa and Qiangtang terranes and ophiolite complex. Clasts of conglomerate contain abundant angular peridotite, gabbro, basalt, chert, andesite, and granite, and minor quartzite and gneiss clasts also exist. Sandstones of the Duoni Formation are dominated by feldspathic-lithic graywacke (Qt25F14L61 and Qm13F14L73), indicative of a mixture of continental-arc and recycled-orogen source origin. Detrital minerals of chromite, clinopyroxene, epidote, and hornblende in sandstone also indicate an origin of ultramafic and mafic rocks, while garnets indicate a metamorphosed source. Paleocurrent data demonstrate bidirectional (southward and northward) source origins. Thus, we suggest that the deposition of the Duoni Formation took place in the processes of the Lhasa-Qiangtang collision during the latest Early Cretaceous (~ 113 Ma), and the BNTO had been closed by this time. Copyright ? 2019, SEPM (Society for Sedimentary Geology) |
URI: | https://www.scopus.com/inward/record.uri?eid=2-s2.0-85075741790&doi=10.2110%2fjsr.2019.55&partnerID=40&md5=eeecd90ca6d85cabb1cec305b4c05267 https://scholars.lib.ntu.edu.tw/handle/123456789/571682 |
ISSN: | 15271404 | DOI: | 10.2110/jsr.2019.55 |
顯示於: | 地質科學系 |
在 IR 系統中的文件,除了特別指名其著作權條款之外,均受到著作權保護,並且保留所有的權利。