Neoproterozoic Foreign Low-Grade Metamorphic Slices in the Western Beihuaiyang Zone of the Dabie Orogen and Their Tectonic Significance

详细信息   

• 责任者：Liu Yican (Key Laboratory of Crust-Mantle Materials and Environments ; CAS ; University of Science and Technology of China ; Hefei 230026 ; China) ; Liu Lixiang
• 刊名：Chinese Journal of Geology
• 出版年：2011
• 卷期：46(2)
• 关键词：浅层变质作用 ; anchimetamorphism ; 变火山岩 ; metavolcanic rocks ; 大地构造 ; tectonics ; 大别山 ; Dabie Mountains
• 页码：p.273-287
• 图表：6 illus., 55 refs.
• 分类号：0802
• issnNo：ISSN0563-5020
• isbnNo：CN11-1937/P

摘要

///The Neoproterozoic foreign low-grade metamorphic slices in the western Beihuaiyang zone of the Dabie orogen are at least composed of two types of rocks such as metagranite and meta-gabbro, which occur as tectonic blocks or slices within the Ordovician metavolcanics of the Dingyuan Formation. These Neoproterozoic low-grade rocks experienced epidote-amphibolite facies metamorphism and strong structural deformation. Their formation timing is 750~720 Ma for the metagranite and 635 Ma for the metagabbro, respectively. In view of their tectonic relationships to country rocks, it is most likely that these Neoproterozoic low-grade rocks are exotic and they might been detached and scraped off from the subducted continental crust of the SCB crust during the initial stage of subduction at Early Triassic, and subsequently exhumed and thrusted over Paleozoic metamorphosed rocks in the southern margin of the North China Block during continental collision.