Petrogenesis of the Late-Triassic Alkaline Magmatism in the Jiaodong Area: Evidence from U-Pb Age, Hf-O Isotopes of Zircons
详细信息
- 责任者：Chen Jingzhi (State Key Laboratory of Lithospheric Evolution ; Institute of Geology and Geophysics ; Chinese Academy of Sciences ; Beijing 100029 ; China) ; Jiang Neng
- 刊名：Acta Petrologica Sinica
- 出版年：2011
- 卷期：27(12)
- 关键词：碱性岩 ; alkali rocks ; 铀—铅计时 ; U-Pb dating ; 铪同位素 ; hafnium isotopes ; 氧同位素 ; oxygen isotopes ; 山东 ; Shandong Province
- 页码：p.3557-3574
- 图表：8 illus., 5 tables, 60 refs.
- 分类号：0801
- issnNo：ISSN1000-0569
- isbnNo：CN11-1922/P
摘要
The Late Triassic alkaline magmatism in Weihai, East Shandong Province, northern part of the Su-Lu UHP belt, is remarkable because its forming time was close to closure time of the Dabie-Sulu Orogen (240~225 Ma). Based on the information of Neoproterozoic ages and 18O depletion of zircons from one of the intermediate dikes and one syenitic dike, the authors suggest that the subducted Yangtze crust could have been contributed to the Late Triassic magmatism, and the Late Triassic alkaline rocks in this area were derived from partial melting of the subducted Yangtze lithospheric mantle and crust, coupled with subsequent fractionation. This magmatism would have driven by heat brought from asthenosphere upwelling due to the subduction of the South China Block beneath the North China Block during Triassic.