K-Ar Geochronology of Mesozoic Mafic Dikes in Shandong Province, Eastern China: Implications for Crustal Extension

作     者：LIUShen HURuizhon ZHAOJunhong FENGCaixia 

作者机构：InstituteofGeochemistryChineseAcademyofSciencesGuiyangGuizhou550002 

出 版 物：《Acta Geologica Sinica(English Edition)》 (地质学报（英文版）)

年 卷 期：2004年第78卷第6期

页      面：1207-1213页

核心收录：

学科分类：070904[理学-构造地质学] 070903[理学-古生物学与地层学(含：古人类学)] 0709[理学-地质学] 07[理学] 

基　　金：This study was supported jointly by the Project of Knowledge Innovation of Chinese Academy of Sciences(KZCX3-SW-125) 

主　　题：crustal extension mafic dike K-Ar age mantle plume Tanlu fault Shandong eastern China 

摘      要：Based on K-Ar isotope analyses, Mesozoic mafic (and alkali ultramafic) dikes from western and eastern Shandong Province, China, are dated at 88.2±1.70 Ma to 169.5±3.7 Ma with the majority of ages ranging from 90 Ma to 140 Ma. The emplacement of the dikes suggests a major Yanshanian (Cretaceous) crustal extension in Shandong province. Together with other available age data, this study suggests four periods of crustal extension at about 80 Ma, 100 Ma, 120 Ma and 140 Ma, respectively. Besides the effect of collapse of the Yanshanian orogenic belt on the emplacement of the mafic dikes in Shandong in the Cretaceous, the mantle plume and the extensive left-lateral advection and extension of the Tanlu fault also have controlled the crustal extension and the emplacement of the mafic dikes in eastern Shandong and western Shandong, respectively.