Identification of the Eclogites with Different Ages and Their Tectonic Significance in
详细信息
- 责任者：Zhang Xiuzheng (Research Center for Tibetan Plateau ; Jilin University ; Changchun 130061 ; China) ; Dong Yongsheng
- 刊名：Geological Bulletin of China
- 出版年：2010
- 卷期：29(12)
- 关键词：榴辉岩 ; eclogite ; 氩—氩计时 ; Ar-Ar dating ; 羌塘盆地 ; Qiangtang Basin
- 页码：p.1815-1824
- 图表：4 illus., 3 tables, 61 refs.
- 分类号：0802
- issnNo：ISSN1671-2552
- isbnNo：CN11-4648/P
摘要
The high pressure metamorphic belt in central Qiangtang consists of eclogite, glaucophane schist and garnet-muscovite schist. In this paper, the authors focus on the eclogites in Pianshishan and Guoganjianianshan area. The Pianshishan eclogites enclosed within garnet-muscovite schist have peak metamorphic p-T conditions at T=500℃ and p=2.3 GPa.The ages ranging between 230 and 244 Ma are given by U-Pb dating of zircons and Lu-Hf datings,and were interpreted as the peak metamorphic age of eclogites. Ar-Ar datings of eclogites and their country rocks gave similar ages ranging between 210 and 220 Ma, representing the cooling age of the eclogites during retrograde metamorphism.