Zircon U-Pb Age, Element and Sr-Nd-Hf Isotope Geochemistry of Late Mesozoic Magmatism from the Guichi Metallogenic District in the Middle and Lower Reaches of the Yangtze River Region
详细信息
- 责任者：Liu Yuanyuan (Faculty of Earth Sciences ; China University of Geosciences ; Wuhan 430074 ; China) ; Ma Changqian
- 刊名：Acta Petrologica Sinica
- 出版年：2012
- 卷期：28(10)
- 关键词：矿集区 ; ore-concentrated area ; A型花岗岩 ; A-type granite ; 岩石地球化学 ; lithogeochemistry ; 安徽 ; Anhui Province
- 页码：p.3287-3305
- 图表：illus., 4 tables, 114 refs.
- 分类号：1001
- issnNo：ISSN1000-0569
- isbnNo：CN11-1922/P
摘要
Zircon U-Pb ages,elemental and Sr-Nd-Hf isotopic data are reported for Late Mesozoic plutons in the Guichi metallogenic district in the Middle and Lower Reaches of the Yangtze River Region, attempting to constrain their age,petrogenesis, and tectonic implications. The Matou granodiorite porphyry and the Huayuangong quartz monzonite were dated at (147±2) Ma and (127±1) Ma,respectively. The early Matou and Tongshan granodiorite porphyries are high-K calc-alkaline,and exhibit adakite-like geochemical features, such as high Al2O3,Sr,Sr/Y and La/Yb values,and low Y and Yb contents.The 127 Ma Huayuangong quartz monzonites and quartz syenites are shoshonitic,and characterized by high(Na2O+K2O),Zr,Nb,Y,Y/Nb and Yb/Ta values,indicating A2-type granite affinity at convergent margins.The 125~124 Ma Huangyuangong alkali feldspar granites also exhibit A-type granite geochemical features,while are characterized by lower Y/Nb and Yb/Ta values,resembling A1-type granite affinity in interplate settings.The change of geochemical features from adakitic rocks to A-type granite is magmatic response to tectonic transition,switching from a continental margin environments to a lithosphere extensional regime.