Chronology and Geochemical Characteristics of K-Feldspar Granite in the Guoqing Tungsten Deposit and Their Geological Implications
详细信息
- 责任者：Li Peng (State Key Laboratory of Geological Processes and Mineral Resources ; Faculty of Resources ; China University of Geosciences ; Wuhan 430074 ; China) ; Lü Xinbiao
- 刊名：Acta Petrologica et Mineralogica
- 出版年：2011
- 卷期：30(1)
- 关键词：花岗岩 ; granite ; 内蒙古 ; Inner Mongolia
- 页码：p.13-24
- 图表：9 illus., 2 tables, 32 refs.
- 分类号：0801
- issnNo：ISSN1000-6524
- isbnNo：CN11-1966/P
摘要
Located near Pantuoshan district in Ejina Banner of southwestern Mongolia, Guoqing K-feldspar granite body lies in southern Niujuanzi-Xichangjing suture zone. LA-ICP-MS U-Pb isotopic dating of zircon separated form the rock yields an average weighted 206Pb/238U age of (439.1±8) Ma. The results of geochemical study indicate that SiO2 are in the range of 73.31%～74.36%, A/CNK>1.1, and K2O/Na2O=1.25～1.40, the Rittmann index of K-feldspar granite varies from 2.06 to 2.22, suggesting a high-K calc-alkaline series and peraluminous nature. The results also indicate that Guoqing K-feldspar granite body is highly enriched in large ion lithophile elements and strongly depleted in high field strength elements. The chondrite-normalized REE and trace elements patterns demonstrate low fractionation level between LREE and HREE, (La/Yb)N=3.40～5.44, and negative Eu(δEu=0.65～0.77), which might have been related to the plagioclase residuals during the partial melt of the original rock.