Zircon U-Pb Age and Hf Isotopic Composition of the Volcanic and Sub-Volcanic Rocks in the Ningwu Basin and Their Geological Implications

• 责任者：Hou Kejun (State Key Laboratory of Geological Processes and Mineral Resources ; China University of Geosciences ; Beijing100083 ; China) ; Yuan Shunda
• 刊名：Acta Petrologica Sinica
• 出版年：2010
• 卷期：26(3)
• 关键词：火山岩 ; volcanic rocks ; 浅成岩 ; hypabyssal rocks ; 铀—铅计时 ; U-Pb dating
• 页码：p.888-902
• 图表：6 illus., 4 tables, 46 refs.
• 分类号：0801, 1300
• issnNo：ISSN1000-0569
• isbnNo：CN11-1922/P

Detailed zircon U-Pb age and Hf isotope measurements were done on the igneous rocks from Ningwu volcanic basin．The results show that all the igneous rocks formed in the Early Cretaceous．Compared with the existed data of other volcanic basins, it can be concluded that there were no Jurassic volcanic activities in all volcanic basins in the Middle and Lower Reaches of the Yangtze River area，and the volcanic activity was happened from 135 Ma to 124 Ma．Zircon Hf isotope analyses of the igneous rocks show relatively homogeneous Hf isotopic compositions．These results show that the parental magmas were mainly derived from an enriched mantle and partly mixed with the lower continental crust rocks, controlled by the environment of the lithosphere extension．