Structural Characteristics and Prospecting Significance of the Xitian Tin-Tungsten Polymetallic Deposit, Hunan Province, China

详细信息   

• 责任者：Wu Shichong (No.416 Geological Team ; Bureau of Geology and Mineral Exploration and Development of Hunan Province ; Zhuzhou 412007 ; China) ; Long Ziqiang
• 刊名：Geotectonica et Metallogenia
• 出版年：2012
• 卷期：36(2)
• 关键词：锡矿 ; tin ores ; 钨矿 ; tungsten ores ; 多金属矿 ; polymetallic ores ; 成矿构造 ; metallotectonics ; 湖南 ; Hunan Province
• 页码：p.217-226
• 图表：5 illus., 32 tables, 2 refs.
• 分类号：1001
• issnNo：ISSN1001-1552
• isbnNo：CN44-1595/P

摘要

The Xitian tin-tungsten deposit, an important deposit discovered recently in the Nanling ore-forming province, occurs in the contact zone of the Late Devonian dolomitic limestone and Jurassic to Cretaceous （ Yans- hanian） granitoids. The main ore types of the deposit are skan-, structural skan-, structural altered rock- and quartz-greisen vein types. There is a SN-trending extensional structure of granite dome, a series of NE-trending multiple folds and NE or NEE-trending strike-slip tectonic system developed in the Xitian deposit. The dome struc- ture is composed of Indosian and Yanshanian granites, Paleozoic strata and Mesozoic discontinuous ring detachment faults, which controls the distribution of skarn orebodies. The complex fold is a NE-trending complicated synelines, which consists of Palaeozoic strata, and is cut by strike-slip faults in the anticlinal core. Some structural fracture zone type ore bodies are controlled by both the coaxial overprinted fold of two periods, which belong to Yantang and Xiaotian complicated syncline, and the ductile brittle shear faults. The strike-slip system consists of the first-order NE-trending right lateral strike-slip faults, secondary P-orientation shear faults, SN-trending left laterial strike-slip faults and NW-trending stretch faults. The strike-slip system controls the distribution of quartz-vein- and greisen vein type tin-tungsten polymetallie orebodies. Zircon SHRIMP and LA-ICPMS U-Pb dating of the Xitian granites and ^40Ar-^39Ar ages of muscovites from the greisenization type tungsten-tin orebodies as well as Re-Os isochron age of molybdenites from the quartz-vein type tin-tungsten ore bodies demonstrate that the time of tectonic activity, mag- matism and metallogenesis in Xitian tin- tungsten deposit is basically consistent with those of the large-scale metal- logeny in Nanling ore-forming province （150 Ma - 160 Ma）. There exist many metallogenic areas favorable for fu- ture exploration, such as contact zones of granites and limestones, NEE- or NE- trending fault zones in the granite dome, and anticlinal cores overprinted by the Yanshanian NE-trending strike-slip faults in the strata.