U-Pb dating for detrital zircons from the Bima Formation, Tinggong, Tibet

The Sangri Group is widely distributed in the middle-east section of the Gangdise volcanic-magmatic arc, which is a representative record of the subduction of the New Tethys Ocean. The U-Pb dating for the detrital zircons from the Bima Formation of the Sangri Group in Tinggong area shows four ages, which are 85.7-143.5Ma,160.2-191.2Ma,334.4-364.1Ma and 904Ma respectively. Combining the youngest age (85.7±1.9Ma) with fossils obtained from the Bima Formation, the authors believe that the Bima Formation was formed between the early Cretaceous and the late Cretaceous, and its sedimentary materials were from the eroded volcanic-magmatic areas of the Lhasa block.