- 责任者：Zhang Lei (Institute of Geology ; Chinese Academy of Geological Sciences ; Beijing 100037 ; China) ; Shi Xingjun
- 刊名：Geological Bulletin of China
- 出版年：2013
- 卷期：32(10)
- 关键词：辉长岩 ; gabbros ; 铀—铅计时 ; U-Pb dating ; 内蒙古 ; Inner Mongolia
- 页码：p.1536-1547
- 图表：8 illus., 2 tables, 45 refs.
- 分类号：0801
- issnNo：ISSN1671-2552
- isbnNo：CN11-4648/P
In Qinggeletu area of northern Alxa within Inner Mongolia, several mafic plutons are sporadically outcropped, of which the Taohaotuoxiquan gabbro is the largest one. These mafic plutons were previously considered to be Early Paleozoic in age. LA-ICP- MS zircon U-Pb dating of two samples from Taohaotuoxiquan gabbro yielded a consistent age of 276-275Ma, suggesting an em- placement of Early Permian. Geochemical characteristics of the Taohaotuoxiquan gabbro indicate that it contains some fractional crys- tallized plagioclase with the Nb negative anomaly inherited from its source, implying that this gabbro was formed in a subduction set- ting rather than in the continental rift. Combined with previous studies, the authors hold that a large amount of mantle-derived melt was involved in Late Carboniferous-Permian magmatism in northern Alxa, and this area might have been an arc in a subduction set- ting at that time.