Fission track age of granite batholith from Southern Tibet: implications for the plateau uplift

Abstract Fission track (FT) ages of apatite and zircon from four granite batholiths from Lhasa and Shannan areas are measured. The FT ages of apatite range from 3.2 to 8.3 Ma, corresponding to the uplift rates of 0.12 to 0.20 mm·a−1 during this period. The uplift height is 580 m, showing that there is not large-scale rapid uplifting in southern Tibet from 3.2 to 8.3 Ma. The zircon FT ages of Lhasa batholith are 25.9 ± 1.7 and 32.7 ± 2.8 Ma, yielding an uplift rate of 0.08mm·a−1 between 26 and 33 Ma. Combining this work with other studies, it is suggested that the average uplift rate in southern Tibet is low from the time of collision between India and Asian continents to ∼3 Ma. The uplift of Tibetan Plateau seems to have finished in multi-stage processes with varied rates.