Multi-Stage Uplift and Exhumation of the West Tianshan Mountain: Evidence from the Apatite Fission-Track Dating

The apatite fission track dating method has been widely applied in the study of the uplift and exhumation history of mountains. The uplifting process of the Tianshan Mountains has long been controversial, and still less attention has been paid to the West Tianshan Mountain. A series of samples, consisting of granite and some other volcanic rocks, were collected from three sections across the Chahanwushu Mountain of West Tianshan, and apatite was chosen for fission track dating in the laboratory. The results reveal that the West Tianshan Mountain has probably experienced multi-stage uplifting and exhumation events. Further temperature-time modeling of apatite was conducted on the basis of analytical data of the fission track length. Combined with studies of regional data, it is suggested that there existed four stages of rapid cooling and uplifting events in the West Tianshan Mountain during the Mesozoic-Cenozoic period, i.e., from Late Triassic to Early Jurassic (220～180 Ma), in Middle Jurassic (160～130 Ma), in Middle-Late Cretaceous (110～80 Ma), and in Late Cenozoic (since ca.24 Ma).