~(40)Ar/~(39)Ar ISOTOPIC DATING OF INTRUSIONS FROM HUOSHAN-SHUCHENG SYENITE ZONE, ANHUI PROVINCE
Zhou Taixi Chen Jiangfeng Li Xueming (Department of Earth and Space Science,University of Science and Technology of China,Hefei,230026) Foland K.A. (Department of Geological Science,The Ohio State University,Columbus,USA) ~(40)Ar/~(39)Ar dating,syenite intrusions,Huoshan-Shucheng region,Anhui Province
Syenite intrusions outcropped in Huoshan-Shucheng region, Auhui province are dated using ~(40)Ar/ ~(39)Ar technique. Gongwan Baochong monzonite, Xianghongdian nepheline syenite and syenite, Xitangchi granite and quartz syenite-porphyry are 126, 122, 123, 121, and 124 Ma respectively in age. The age range of the dated syenite intrusions is identical to one of the granite intrusions of the same region. They were all emplaced in Cretaceous period and belong to the active Yanshanian magmatism of East China. Cretaceous age for syenites from this region suggests that collision between the Sino-Korean and Yangtze blocks was finished and a post-collision extrusion was prevailed by that time.