- 责任者：Quan Jingyu (College of Earth Science ; Jilin University ; Changchun 130061 ; China) ; Chi Xiaoguo
- 刊名：Geological Bulletin of China
- 出版年：2013
- 卷期：32(2/3)
- 关键词：片岩 ; schist ; 铀—铅计时 ; U-Pb dating ; 松嫩平原 ; Songnen Plain
- 页码：p.353-364
- 图表：illus., 2 tables, 40 refs.
- 分类号：0802
- issnNo：ISSN1671-2552
- isbnNo：CN11-4648/P
LA-ICP-MS U-Pb dating was conducted for detrital zircon from Liangzihe Formation of Dongfengshan Group and Hongguang Formation of ＂Zhangguangcai Ling Group＂ Precambrian metamorphic rock series in eastern Songnen masiff within Xiao Hinggan Mountains and Zhangguangcai Mountain regions. Three peak ages are shown for the garnet-biotite schist of Liangzihe Formarion in Chenming Township, i.e., 757Ma±9Ma,917Ma±10Ma and 1709Ma±75Ma, and two major peak ages are shown for the altered andalusite-two-mica schist of Hongguang Formation in Diaoyutai area, i.e., 843Ma±10Ma and 9271Ma±6Ma. Besides, some dispersed zircon ages from 2495Ma to 1012Ma were also found. These data indicate that the Dongfengshan Group was formed in Neoproterozoic. Combined with regional stratigraphy, the protolith assemblages of Dongfengshan Group should be a set of meso- and epi-metamorphic strata which were composed of mudstone rocks, limestone rocks, carbonaceous mudstones and sandstones with high boron content and formed in the stable continental margin. Based on field investigation, petrography, zircon U-Pb geochronology in combination with recent researches and reports on ＂Zhangguangcai Ling Group＂, the authors hold that the originaUy defined ＂Zhang- guangcai Ling Group＂ is not a unified integration but is made up of a series of granitic rocks and moderately to slightly metamorphosed rocks with different ages. A part of Al-rich paragneisses, Al-rich mica-schists and strongly deformed marbles of originally assigned to ＂Zhangguangcai Ling Group＂ should belong to Neoproterozoic Dongfengshan Group. The zircon U-Pb dating results indicate that the rocks mainly exposed in the source region of these metamorphic rocks include Grenville phrase rocks related to Rodinia supercontinent formation.