Tracking multi-stage uplift history of the Eastern Tianshan Orogenic Belt during the Late Carboniferous and Early Cretaceous: Evidence from apatite U-Pb and fission track data

This work presents new apatite fission track (AFT) and U-Pb data for intrusions collected from Yamansu-Caixiashan region based on in situ U-Pb and FT dating methods by using LA-ICP-MS. Combined with zircon U-Pb dating results, these intrusions were emplaced in Carboniferous (357 similar to 309Ma) and Triassic (ca. 252Ma). Our AFT data gave a wide range of ages from 304Ma to 118Ma. Three fast cooling stages were obtained by thermochronology data and thermal history modeling: Late Carboniferous-Early Permian (320 similar to 280Ma), Middle-Late Triassic (240 similar to 210Ma), and Early Cretaceous (120 similar to 100Ma), respectively. The above data indicate that the Eastern Tianshan Orogenic Belt (ETOB) experienced multi-stage uplift history during the Late Paleozoic-Early Mesozoic. The new data, in combination with previous research results, allow us to understand the mechanism of complicated uplift processes in the ETOB. The first stage of uplift evolution was caused by the Late Paleozoic collision orogeny in the study area. The second stage was likely related to the closure of the Paleo-Tethys Ocean and the consequence collisions of the Songpan-Ganzi the Qiangtang terranes to the southern margin of the Eurasian plate. The third stage was mainly caused by the collision between the Qiangtang and Lhasa terranes. The ETOB experienced significant differential uplift since the Late Paleozoic, which can be related to the inhomogeneity and fragmentation of tectonic units in the region, as well as differences in the geological history of these units. External driving forces and reactivation of pre-existed faults also affected the uplift processes.