Discussions on the Tectonic Setting of Caledonian Granitoids in the Eastern Segment of South China

• 责任者：Zhang Fangrong (School of Earth Sciences and Engineering ; Nanjing University ; Nanjing 210093 ; China) ; Shu Liangshu
• 刊名：Earth Science Frontiers
• 出版年：2009
• 卷期：16(1)
• 页码：p.248-260
• 图表：5 illus., 2 tables, 68 refs.
• issnNo：ISSN1005-2321
• isbnNo：CN11-3370/P

Based on our newly firsthand data obtained recently from regional geological survey and previous research results, we have analyzed in detail the geological features, distribution, forming ages and Nd-Sr isotopic characteristics of Caledonian granitoids in the eastern segment of South China. The tectonic setting forming Caledonian granitoids were discussed, which includes the ages of ultramaficmafic rocks and volcanic rocks that outcrop in the study areas, the deposited environment of sedimentary rocks during the Sinian-Ordovician period, and deformation patterns of the Caledonian structures.Results suggest that the Caledonian granitoids were mainly formed between 410-460 Ma corresponding to the period from the Middle Ordovician to the Early Devonian. Geochemically, most of granitoids belong to the S-type that their magma were derived from the partial fusion of continental crust,but a few granitoids show characteristics of type-I granitoids that the magma contains mantle materials. The authors propose that the tectonic setting forming Caledonian granitoids mainly belongs to intraplate tectonic environment.