An approach to the Neogene uplift rates for the eastern Qinghai-Xizang Plateau: Evidence from the fission track ages of the apatite from the Chola granites in western Sichuan

The fission-track analysis is made for the apatite from the Chola granites in western Sichuan in the eastern part of the Qinghai-Xizang Plateau, and gives four fission track ages:4.9 ±0.3 Ma, 6.2 ±0.5 Ma, 7.2 ±0.4 Ma and 7.3 ±0.7 Ma, which have disclosed that the Chola Mountains began to uplift at ca. 7.3 Ma BP. With the aid of fission-track analysis-elevation method, the uplift rates of the Chola Mountains are calculated as 0.15-2 mm/a, with an average of 0.78 mm/a since the Miocene. On the whole, the uplifting of the Chola Mountains displays the evolutionary processes from the rapid uplift to the slow uplift. The results of research in this study may be helpful to the study of the uplift of the eastern Qinghai-Xizang Plateau.