Petrology and Geochemistry of Intrusive Rocks in the Ga’erqiong-Galale Ore Concentration Area, Tibet and Their Geological Implications
详细信息
- 责任者：Zhang Zhi (Chengdu University of Technology ; Chengdu 610059 ; China) ; Tang Juxing
- 刊名：Geology and Prospecting
- 出版年：2013
- 卷期：49(4)
- 关键词：火成岩 ; igneous rocks ; 岩石地球化学 ; lithogeochemistry ; 西藏 ; Tibet
- 页码：p.676-688
- 图表：illus., 3 tables, 31 refs.
- 分类号：0801
- issnNo：ISSN0495-5331
- isbnNo：CN11-2043/P
摘要
The Ga’erqiong-Galale ore-concentration area,located in the western segment of the Bangong-Nujiang metallogenic belt,is a skarn (porphyry) copper-gold ore concentration area where significant exploration breakthrough has been achieved in recent years. The Gaerqiong and Galale copper-gold deposits have been discovered in this ore concentration area. The types of the intrusive rocks include GL (Galale) granodiorite,GL granite porphyry,GL diorite,GE (Gaerqiong) granite porphyry and GE quartz diorite. Geochemical characteristics indicate that the ω(SiO2): 53.68%~80.78%,ω(Al2O3): 8.51%~16.91%,A/CNK: 0.54~1.11,implying that the intrusive rocks are of metaluminous-weakly metaluminous calc-alkaline-K calc-alkaline stocks. Geochemical characteristics of trace elements and rare earth elements indicate that the intrusive rocks are enriched in Rb,Sr and Th,and depleted in Ta,Nb,Hf,Zr,Yb and Ti. All the intrusive rocks have negative anomalies of Nb,Ta and Ti,and the GE granite porphyry deficits Sr and Ti especially. Distinguishing of the petrogenesis type indicates that GE granite is granite of S-type,others are granite of I-type. Identification of tectonic environments suggests that the intrusive rocks in ore concentration area were formed in the stage of the collision uplift after the closing of the Bangong-Nujiang Tethys ocean.