|Abstract:The Shangxu gold deposit locates to the south of the middle part of the Bangong-Nujiang suture zone in northern Tibet. In this paper, we use situ U-Pb dating on detrital zircons from the Middle-Lower Jurassic metasedimentary rocks in Shangxu for tracing their provenance. The analysis on 114 detrital zircons of varying size and shape, which were selected randomly, shows that: (1) zircons are 80 μm ~ 150 μm long, and Th/U ratios of most zircons are higher than 0.4; (2) ages of detrital zircons range from 223 to 2615 Ma, with five peaks ca.280, ca.451, ca.908, ca.1900 and ca.2430 Ma. By contrasting detrital zircon chronology for the Middle-Lower Jurassic metasedimentary rocks in Shangxu with those in Lhasa and southern Qiangtang terranes, an important observation is that the ca.908Ma age population characteristic of detrital zircons in Shangxu is consistent with the distinctive ca.950Ma age peak in detrital zircons from the western Qiangtang terrane, rather than distinctive ca.1170Ma age peak in detrital zircons from the Lhasa terrane. We interpreted the age (223Ma) close to its depositional age. The result indicates that the provenance of Middle-Lower Jurassic Mugagangri Group in Shangxu probably is remnants of the Bangong-Nujiang oceanic basin, implying the northward subduction of the Bangong-Nujiang Ocean beneath southern Qiangtang terrane.