Discovery of the Paleoproterozoic Terrane in Lhasa Block, Qinghai-Tibet Plateau
详细信息
- 责任者：He Shiping (Xi’an Institute of Geology and Mineral Resources ; Xi’an 710054 ; China) ; Li Rongshe
- 刊名：Earth Science
- 出版年：2013
- 卷期：38(3)
- 关键词：地体 ; terranes ; 青藏高原 ; Qinghai-Tibetan Plateau
- 页码：p.519-528
- 图表：illus., 1 table, 50 refs.
- 分类号：0300
- issnNo：ISSN1000-2383
- isbnNo：CN42-1233/P
摘要
Songduo rock group includes Chashagang rock formation,Mabuku rock formation and Leilongku rock formation,which takes on fault blocks locating in the eastern Lhasa block,and its age has long been argued.The high accurate LA-ICP-MS zircon U-Pb isotope dating of meta-basic volcanic rock from Chashagang rock formation in Gongbujiangda County,Tibet,yielded a U-Pb upper-intercept age of 2 450.3±9.9 Ma.It is suggested a rock-forming age and the oldest isotopic age of basement of Lhasa block,belonging to the Early Paleoproterozoic.According to field investigation and the new data of geochronology,combining with new results from regional geological survey,we propose that "the original Songduo rock group" should be disintergrated,and re-establish a Gongbujiangda rock group.The Songduo rock Group only remain Mabuku rock formation(AnOm)and Leilongku rock Formation(AnOl).It is great significance to redefinite the Precambrian basement framework,compare in region,subdivide tectonic units,and find minerals related with the Precambrian.