Late Paleozoic Arc-Related Magmatism in Yakeshi Region,
详细信息
- 责任者：Zhao Zhi (College of Earth Sciences ; Jilin University ; Changchun 130061 ; China) ; Chi Xiaoguo
- 刊名：Acta Petrologica Sinica
- 出版年：2010
- 卷期：26(11)
- 关键词：火成岩 ; igneous rocks ; 岛弧 ; island arc ; 岩石地球化学 ; lithogeochemistry ; 内蒙古 ; Inner Mongolia
- 页码：p.3245-3258
- 图表：5 illus., 4 tables, 60 refs.
- 分类号：0801
- issnNo：ISSN1000-0569
- isbnNo：CN11-1922/P
摘要
Arc volcanic rocks and adakitic granodiorites are identified to occur within the Late Paleozoic magmatite in Yakeshi region, Inner Mongolia. The volcanic rocks, which consist of calc-alkaline basalts, andesites and dacites, are characterized by strong enrichment of light rare earth elements (LREE), large ion lithophile elements (LILE) and depletion of high field strength elements (HFSE). SHRIMP zircon U-Pb isotopic dating revealed that the basalt was formed at 373.2±5.3Ma. The zircon εHf(t) values are within a range from +14.67 to +18.67, which are similar to the Hf isotope feature of mid-oceanic ridge basalt (MORB) and modern subduction zone basalt. These characteristics suggest that the basalts were formed in an active continental margin and from the melting of a depleted mantle wedge modified by predominant slab fluids. A zircon U-Pb chronological date yield an age of 331.2±3.7 Ma, interpreted as emplacement age of the granodiorites.