^40Ar/^39Ar dating of Daqingshan thrust

作     者：LIU Zhenghong, XU Zhongyuan & YANG Zhensheng College of Earth Sciences, Jilin University, Changchun 130061, China Correspondence should be addressed to Liu Zhenghong (e-mail: liuzhenghong@***) 

作者机构：College of Earth Sciences Jilin University Changchun China 

出 版 物：《Chinese Science Bulletin》 (Chin. Sci. Bull.)

年 卷 期：2003年第48卷第24期

页      面：2734-2738页

核心收录：

学科分类：070902[理学-地球化学] 0709[理学-地质学] 07[理学] 

基　　金：supported by the China Geological Survey Project(Grant No.2000113000021) the Innovation Fund of Jilin University(Grant No.450011022009) 

主　　题：Ar 氩 中生代 云母 同位素 

摘      要：The Daqingshan thrust system, to the south of the Shiguai Mesozoic basin, is a complex system of top-to- the-north thrusting tectonic sheets. The thrust system has a complicated evolution due to multi-stage thrusting. In order to date the thrusting events, syntectonic muscovite and bio-tite grains are respectively analyzed with normal 40Ar/39Ar dating and laser 40Ar/39Ar dating, which yield 2 isochron ages, i.e. 193.74 3.88 Ma and 121.6 1.6 Ma. These ages suggest that faults within the Daqingshan thrust system formed dur-ing 2 stages of thrusting, one the early Indosinian and the other the late Yanshanian. The isotopic dating is consistent with field geological relations. Indosinan deformation is evi-denced by top-to-the-north thrusting, with the occurrence of a series of large-scale east-west trending thrust faults and folds, while the Yanshanian thrusting is characterized by top-to-the-NNW thrusting. It is superposed on and modifies early Indosinian thrust faults.