Modelling of low-temperature exhumation rate in Dabie Mountain based on (U-Th)/He and fission-track thermochronological data  

作　　者：DING Ruxin ZHOU Zuyi XU Changhai LIU Yuzhu CHENG Hao XU Fei 

机构地区：[1]State Key Laboratory of Marine Geology,Tongji University,Shanghai 200092,China State Key Laboratory of Marine Geology,Tongji University,Shanghai 200092,China State Key Laboratory of Marine Geology,Tongji University,Shanghai 200092,China State Key Laboratory of Marine Geology,Tongji University,Shanghai 200092,China State Key Laboratory of Marine Geology,Tongji University,Shanghai 200092,China State Key Laboratory of Marine Geology,Tongji University,Shanghai 200092,China

出　　处：《Science China Earth Sciences》2006年第10期1009-1019,共11页中国科学（地球科学英文版）

基　　金：This research was supported by the Chinese National Key Basic Research Special Foundation Project(Grant No.G 2000078501);the National Natural Science Foundation of China(Grant Nos.40272093,40321603 and 40572075).

摘　　要：While the high-temperature exhumation process in the Dabie Mountain has been well documented, the low-temperature exhumation of this area since Cretaceous, especially since Late Cretaceous, is relatively less studied. Low-temperature thermochronology provides one of the important approaches to solve this problem. Based on the data of fission track and (U-Th)/He analysis of apaptites and zircons from the granitoid and metamorphic rocks in the Dabie Mountain, this paper applies Mancktelow’s and Braun’s methods to estimating the exhumation rates and to drawing the regional differential exhumation pattern since Cretaceous, especially since Late Cretaceous by taking into consideration factors such as heat transport, heat advection, topography and heat production, which could influence geothermal field in the shallow crust. Since Cretaceous, the exhumation rate (0.08-0.10 km/Ma) in the region around Tiantangzhai and in the south of Tanlu fault zone is larger than the rate (0.04-0.07 km/Ma) in other areas of the Dabie Mountain. The regional differential exhumation pattern might be related to the push-up effect caused by differential strike-slip movement along NNE-trending faults.While the high-temperature exhumation process in the Dabie Mountain has been well documented, the low-temperature exhumation of this area since Cretaceous, especially since Late Cretaceous, is relatively less studied. Low-temperature thermochronology provides one of the important approaches to solve this problem. Based on the data of fission track and (U-Th)/He analysis of apaptites and zircons from the granitoid and metamorphic rocks in the Dabie Mountain, this paper applies Mancktelow’s and Braun’s methods to estimating the exhumation rates and to drawing the regional differential exhumation pattern since Cretaceous, especially since Late Cretaceous by taking into consideration factors such as heat transport, heat advection, topography and heat production, which could influence geothermal field in the shallow crust. Since Cretaceous, the exhumation rate (0.08-0.10 km/Ma) in the region around Tiantangzhai and in the south of Tanlu fault zone is larger than the rate (0.04-0.07 km/Ma) in other areas of the Dabie Mountain. The regional differential exhumation pattern might be related to the push-up effect caused by differential strike-slip movement along NNE-trending faults.

关 键 词：DABIE Mountain  fission track  (U-Th)/He  modelling  exhumation. 

分 类 号：N[自然科学总论]