Uplift and cooling history of Qiangtang Basin and its significance

The low temperature thermochronology of the Qiangtang Basin was studied by the apatite fission track method based on tectonic and thermal evolution. The uplift and cooling ages recorded in the Qiangtang Basin could be divided into two phases:the first one mainly happened from the late Early Cretaceous to the Late Cretaceous (108.7 to 69.8 Ma) and the second one mainly from the Middle-Late Eocene to the Late Miocene (44.4 to 10.3 Ma). The first phase is an uplift and cooling record of the central uplift belt in the Qiangtang Basin, which was caused by the compression of the closing of the Bangong-Nujiang oceans. The second phase can be further divided into three times:44.4-30.8, 26.1-22.6, and 10.3 Ma, among which the Late Oligocene to Early Miocene (26.1-22.6 Ma) is the main uplift period. The second phase is an uplift and cooling record that was caused by the compression due to the collision of the Indian and Eurasian plates. The apatite fission track method was used to determine the uplift and cooling ages of the basin. The Qinghai-Tibet Plateau began to uplift at 44.4 Ma, and an overall strong uplift took place during 26.1-22.3 Ma. The plateau was formed after the strong uplift, and has continued to uplift since the Late Pliocene (10.3 Ma).