The Discovery and Geological Significance of Proterozoic Intrusive Rock with High-K in the Central of Qimantage Area
详细信息
- 责任者：Ma Wen (Qinghai Geological Survey ; Xining 810001 ; China) ; Ding Yujin
- 刊名：Northwestern Geology
- 出版年：2013
- 卷期：46(1)
- 关键词：片麻岩 ; gneisses ; 昆仑山 ; Kunlun Mountains
- 页码：p.32-39
- 图表：illus., 4 tables, 26 refs.
- 分类号：0802
- issnNo：ISSN1009-6248
- isbnNo：CN61-1149/P
摘要
Five metamorphic intermediate-acid intrusive rock bodies in Proterozoic have been identified in the central Qimantage by the 1∶50000 mineral prospect survey. The intermediate-acid intrusive rock bodies located in amphibolite facies the volcanic-sedimentary rocks are gray-pale flesh red two-feldspar gneiss with eye-shaped. The two-feldspar granites are their original rocks. Zircon U-Pb age is of 832±12 Ma on average, which are known the oldest intermediate-acid intrusive magma products. Geochemistry of rocks is as follows: high K2O (4.92—5.76×10-2), poor FeO, MgO, and CaO. Rocks with high-K are calc-alkaline S-type high-evolution granites that were formed about 34.7 km in crustal thickness. Tectonic setting is shown sys-collision by R1-R2 discriminant diagrams. Rodinia continent closed at about 830 Ma in the East Kunlun. Intermediate-acid magma action reproduced in early Paleozoic. In this process Rodinia breakup and plates in low latitudes moved to high-latitude. The discovery is important to know the structure evolution of early Paleozoic in East Kunlun.