Timing of Late Jurassic Extension in the Yiwulüshan Area, Western Liaoning: Geochronological Evidence from Syn-Kinematic Granitic Dikes
详细信息
- 责任者：Zhang Bilong (School of Resource and Environmental Engineering ; Hefei University of Technology ; Hefei 230009 ; China) ; Zhu Guang
- 刊名：Geological Journal of China Universities
- 出版年：2012
- 卷期：18(4)
- 关键词：伸展作用 ; extension ; 变质核杂岩 ; metamorphic core complexes ; 辽宁 ; Liaoning Province
- 页码：p.647-660
- 图表：2 illus., 1 table, 37 refs.
- 分类号：0300
- issnNo：ISSN1006-7493
- isbnNo：CN32-1440/P
摘要
Yiwulüshan metamorphic core complex (MCC), situated in the eastern Yanshan structural belt, has experienced two phases of crustal extensional activities: an early development of detachment ductile shear zone around the Yiwulüshan pluton under a NNE-SSW extensional regime, and a subsequent truncation of its southwestern segment by later Waziyu ductile shear zone because of a change in extensional direction during doming. In the early extensional period, there were a great deal of syn-kinematic granitic dikes with different deformation styles intruded in the detachment shear zone and its deformed lower plate. LA-ICP-MS zircon U-Pb dating results of these dikes suggest that Yiwulüshan metamorphic core complex was formed between 157 Ma and 149 Ma. The Late Jurassic extensional activities in the Yiwulüshan area imply that destruction might have been happened in the northern part of North China Craton since Late Jurassic and reached peak period throughout the whole eastern North China Craton in the Early Cretaceous.