• 责任者：Guo Qianqian (Key Laboratory of Computational Geodynamics ; Graduate University ; Chinese Academy of Sciences ; Beijing 100049 ; China) ; Xiao Wenjiao
• 刊名：Chinese Journal of Geology
• 出版年：2013
• 卷期：48(1)
• 关键词：浊积岩 ; turbidite ; 构造环境 ; tectonic setting ; 新疆 ; Xinjiang ; 甘肃 ; Gansu Province ; 内蒙古 ; Inner Mongolia
• 页码：p.50-70
• 图表：illus., 4 tables, 54 refs.
• 分类号：0803
• issnNo：ISSN0563-5020
• isbnNo：CN11-1937/P

The Beishan orogen is one of the key parts to study the accretionary orogenesis of the Altaids, and turbidites are an important composition of the accretionary orogenic belt. The Paleozoic turbidites in the Beishan are mainly distributed in the Yingmaotuo, Liuyuan and Heishankou areas. The turbidites in the Yingmaotuo area is Early Ordovician in age and were derived from felsic sources by medium-high weathering degree,indicating a passive continental margin tectonic setting. The turbidites in the Liuyuan area is Early Permian in age, and were derived from intermediate-basic sources by low-medium weathering degree, indicating an oceanic arc tectonic setting. The Heishankou turbidites are a little younger than the Liuyuan turbidites,and were derived from felsic sources by medium weathering degree, indicating a continental arc tectonic setting. Together with other data, we conclude that a complex oceanic subduction process took place in the Beishan orogen in the Paleozoic. There was a northward subduction zone in Huaniushan-Huoshishan area, and to the south of this subduction zone the Yingmaotuo turbidites formed in a passive margin in the Early Paleozoic. In the Late Paleozoic, the subduction zone was retreated southward,forming the Dundunshan arc and the Liuyuan and Heishankou turbidites were formed by two way subductions. Our work supports the Late Paleozoic active margin model and indicates that complicated accretionary orogenesis might have happened until the end Permian or even to the Middle Triassic in the Beishan. Therefore the termination of the CAOB was at least to the end-Permian.