Geological Characteristics and Genesis of Yuleken-Halasu Superimposed and Tectonically Reworked Porphyry Copper-gold(Molybdenum) Deposit in Qinghe, Xinjiang
详细信息
- 责任者：Xiang Peng(Key Laboratory of Mineral Resources ; Institute of Geology and Geophysics ; Chinese Academy of Sciences ; Beijing 100029 ; China) ; Zhang LianChang
- 刊名：Acta Petrologica Sinica
- 出版年：2012
- 卷期：28(8)
- 关键词：斑岩铜矿床 ; porphyry copper deposit ; 斑岩钼矿床 ; porphyry molybdenum deposit ; 金矿 ; gold ores ; 新疆 ; Xinjiang
- 页码：p.2369-2380
- 图表：illus.,1 tables,24 refs.
- 分类号：1001
- issnNo：ISSN1000-0569
- isbnNo：CN11-1922/P
摘要
Yuleken-Halasu porphyry copper-gold (molybdenum) deposit, located in the northwestern section of Kalaxianger porphyry copper metallogenic belt, lies on the northeastern margin of Junggar Basin. Granodiorite porphyry and granite porphyry in Early Hercynian are the main ore-bearing porphyries. The wall rocks are basically a set of volcanic-sedimentary rock series in the Middle Devonian Beitashan Formation, intruded by magmatic rocks in Late Hercynian and Indosinian. Of all the deposits in Kalaxianger metallogenic belt, Yuleken-Halasu deposit is the most intensively deformed. A series of schistositized belts occur in Yuleken-Halasu ore area due to impact of the Erqisi fault. Meanwhile, most of the ore-bearing porphyries and the wall rocks are mylonitized and schistositized inordinately. The main ore rocks are not only mineralized in the form of stockwork and dissemination at the early stage of typical porphyry deposit, but also superimposed in the form of mineralization in the schistosity, mylonitized foliation and cleavage at the late stage. Geochronological study indicates that there are several magmatic and tecton-thermal events in Devonian-Triassic and metallogenic events in Devonian-Carboniferous recorded in the metallogenic belt. Through this article and the previous studies, the metallogenic belt, intruded by mass medium-acidic porphyries, was in the island arc tectonic setting related with oceanic subduction in Middle-Late Devonian (390~360Ma), accompanied by large-scale Cu-Mo mineralization. The whole metallogenic belt went through collision stage with intensely tectonic reworking and superimposed mineralization in Early Carboniferous (360~330Ma). Furthermore, Cu-Mo mineralization was developed along the mylonite foliation. The post-collision stage in Middle-Late Carboniferous (330~300Ma) was characterized by superimposed molybdenite + chalcopyrite + K-feldspar veins mineralization. The metallogenic belt underwent post-orogenic extension stage in Early Permian (270~260Ma), causing Cu-Mo filled and re-enriched in structural fracture cleavage, which resulted in superimposed mineralization developed along the fracture cleavage. In Triassic, the whole metallogenic belt was in intracontinental orogenic stage, accompanied by vein-type superimposed mineralization which was associated with low-angle overthrust faults. Therefore, Yuleken is a typical porphyry deposit which is characterized by superimposition and tectonic reworking.