Geochemistry and Genesis of Pangkaimen Gold-Silver Deposit in Northern Segment of Great Hinggan Mountains
详细信息
- 责任者：Li Xiangwen (College of Earth Sciences ; Jilin University ; Changchun 130061 ; China) ; Yang Yanchen
- 刊名：Journal of Jilin University
- 出版年：2012
- 卷期：42(1)
- 关键词：金矿 ; gold ores ; 银矿 ; silver ores ; 大兴安岭 ; Greater Hinggan Mountains
- 页码：p.82-91
- 图表：8 illus., 4 tables, 17 refs.
- 分类号：1001
- issnNo：ISSN1671-5888
- isbnNo：CN22-1343/P
摘要
Pangkaimen gold-silver deposit is located in Aihui-Huma metallogenic belt,and the main ore bodies are hosted by Jurassic volcanic rocks in Ganhe Formation.The ore body formed as veins which are under strict control of silicified breccia zone.The basaltic andesite,andesite,and rhyolite in Ganhe Formation are the peraluminous high-K calc-alkaline series,and basalt and quartz porphyry are shoshonite series.They derived from mantle and formed as products of co-genetic magma.The fluid inclusions are poorly developed with main type of gas-liquid two-phase inclusions and minor three-phase inclusions with daughter crystals.The homogenization temperature for gas-liquid two-phase inclusion is from 268.8℃ to 331.6℃,and the salinity(contents of NaCl) from 8.67% to 13.11%.The homogenization temperature for three-phase inclusions is from 288.8℃ to 313.3℃,and the salinity from 37.32% to 39.23%.Therefore,the ore-forming fluids are the hydrothermal system with medium temperature,medium to high salinity.According to the analytical results of hydrogen and oxygen isotope,we infer that the hydrothermal system is a mixed fluid of magmatic hydrothermal fluid with atmospheric water.The tectonic setting for this deposit was changed from compress to extension in the Early Cretaceous.The ore-forming material is mainly from deep-seated magma and volcanic rocks,and the mineralization conditions are medium temperature and shallow depth.The genetic type for this deposit is medium temperature epithermal ore deposit.