Mesozoic exhumation of the Jueluotage area, Eastern Tianshan, NW China: constraints from (U–Th)/He and fission-track thermochronology

Abstract

The Jueluotage area, which is located in the southern branch of the Eastern Tianshan and northeast of the Tarim Basin, represents a vital locality for investigating intracontinental reactivation induced by the tectonic events at the Eurasian plate margin. This study applies zircon and apatite (U–Th)/He and apatite fission-track thermochronology to the Jueluotage area in the Eastern Tianshan. Our data and thermal history modelling show that the Jueluotage area experienced Triassic–Early Jurassic (˜240–180 Ma) cooling, reflecting the closure of the North Tianshan Ocean and subsequent far-field effects of collision/accretion of the Qiangtang Block and Kunlun terrane. Following this period of fast cooling, a differential exhumation process occurred between the various tectonic belts in the Jueluotage area. The Aqishan–Yamansu belt was exposed at the surface during the Triassic–Early Jurassic cooling phase and experienced subsequent burial, which continued until Early Cretaceous time when a pulse of exhumation occurred. However, the major fault zones (Kanggurtag ductile shear zone and Aqikkuduk Fault) and Central Tianshan arc have remained tectonically stable since Early Jurassic time. No Cenozoic rapid cooling was recorded by the low-temperature thermochronology results in this study, indicating that much of the Jueluotage area was exhumed to the upper crust in the late Mesozoic period.

A re-evaluation of the Meso-Cenozoic thermo-tectonic evolution of Bogda Shan (Tian Shan, NW China) based on new basement and detrital apatite fission track thermochronology

“…Furthermore, the distinguished age populations (peaks) are in good agreement with the basement cooling ages (both AFT and apatite (U-Th)/He) reported from the Harlik, Kangguer, and Yamansu Arcs in the eastern Chinese Tianshan (e.g. Gillespie et al 2017a;Sun et al 2021;He et al 2022a). The denudation of these basement rocks hence has provided a large volume of sediments to the adjoining and long-lived basins.…”

Late Triassic Intracontinental Deformation of South Tianshan, Central Asia: Evidence from Syn‐tectonic Sedimentation and Detrital Zircon Provenances of the Kuqa Depression

“…In recent years, research on the Mesozoic sedimentary system in Tianshan (Hendrix et al, 1992;Han et al, 2016a;De Pelsmaeker et al, 2018) and detrital zircon U-Pb geochronology in Bogda region and Turpan-Hami Basin (Tan et al, 2014;Wang J et al, 2018;Zhang et al, 2019) indicated a significant surface uplift and exhumation phase of the Tianshan range during the Triassic. In addition, the study of strike-slip deformation in eastern Tianshan (Wang et al, 2010) and tectonothermal events in the Tianshan range (Li and Wang, 1998;Li et al, 2000;Dumitru et al, 2001;Seltmann et al, 2011;Zhao et al, 2020;Sun et al, 2021;He et al, 2022) also indicated obvious Triassic tectonic reactivation in the Tianshan range. However, there is no report about the initial timing and deformation process of the Triassic intracontinental deformation in the Tianshan range, which are crucial to clarify the early construction of the Asia continent in the early Mesozoic.…”