Late early Cretaceous peraluminous biotite granites along the Bangong–Nujiang suture zone, Central Tibet: Products derived by partial melting of metasedimentary rocks?

Lithos ◽  
2019 ◽  
Vol 344-345 ◽  
pp. 147-158
Author(s):  
Wan-Long Hu ◽  
Qiang Wang ◽  
Jin-Hui Yang ◽  
Chunfu Zhang ◽  
Gong-Jian Tang ◽  
...  
Keyword(s):  
Partial Melting ◽  
Early Cretaceous ◽  
Suture Zone ◽  
Metasedimentary Rocks ◽  
Central Tibet

Closure of the Bangong–Nujiang Tethyan Ocean in the central Tibet: Results from the provenance of the Duoni Formation

2019 ◽  
Vol 89 (10) ◽  
pp. 1039-1054 ◽  
Author(s):  
Zhicai Zhu ◽  
Qingguo Zhai ◽  
Peiyuan Hu ◽  
Sunlin Chung ◽  
Yue Tang ◽  
...  
Keyword(s):  
Early Cretaceous ◽  
Late Cretaceous ◽  
Suture Zone ◽  
The Tibetan Plateau ◽  
Tectonic History ◽  
Magmatic Rocks ◽  
Two Samples ◽  
Delta Sequence ◽  
History Of ◽  
Central Tibet

ABSTRACT 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.

Petrogenesis of Late Early Cretaceous high-silica granites from theBangong–Nujiang suture zone, Central Tibet

Lithos ◽  
2020 ◽  
pp. 105788
Author(s):  
Wan-Long Hu ◽  
Qiang Wang ◽  
Jin-Hui Yang ◽  
Gong-Jian Tang ◽  
Lin Ma ◽  
...  
Keyword(s):  
Early Cretaceous ◽  
Suture Zone ◽  
High Silica ◽  
Central Tibet
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