Apatite (U-Th)/He Thermochronology Evidence for Two Cenozoic Denudation Events in the Eastern Part of the Sulu Orogenic Belt.

Li Xu (1) , Wu Lin (2) , Marc Jolivet (3) , Chang'An Li (4) , Haijin Liu (5)

1 China Three Gorges University
2 Institute of Geology & Geophysics, Chinese Academy of Sciences
3 GR - Géosciences Rennes
4 CUG - China University of Geosciences [Wuhan]
5 East China Institute of Technology

The Sulu orogenic belt, located between the North China and South China plates, is one of the most prominent intracontinental orogenic belt in eastern China. Therefore, the denudation history of Sulu orogenic belt provides significant insight into the basin-mountain evolution in eastern China and their dynamic mechanism. Due to the apatite (U-Th)/He system has low closure temperature (ca. 70 °C), it can constrain the cooling processes of geological bodies more accurately in the upper crust. In this study, the apatite (U-Th)/He method was used to analyze the exhumation time of rocks on the Duofu and Juchi Mountains located in the eastern parts of Sulu orogenic belt. The apatite (U-Th)/He age-elevation relationship and thermal history simulation results showed that the exhumation occurred in the Early-Middle Eocene (54-43 Ma) and Oligocene (35-27 Ma) for the Duofu and Juchi Mountains, respectively. These cooling episodes were synchronized with the exhumation time of the western part of the Sulu orogenic belt. Combined with the results reported in the region, it is showed that the eastern China was influenced by the Pacific and Indian plates subduction into Eurasia, and the extensive exhumation process occurred in the Early Cenozoic, which established the basin-mountain distribution pattern during this time.

Domaines: Géochimie

Li Xu, Wu Lin, Marc Jolivet, Chang'An Li, Haijin Liu. Apatite (U-Th)/He Thermochronology Evidence for Two Cenozoic Denudation Events in the Eastern Part of the Sulu Orogenic Belt.. Earth Science, 2022, 47 (4), 16 p. ⟨10.3799/dqkx.2019.000⟩. ⟨insu-03601008⟩