江西永丰地区萤石矿成矿地质条件与成因探讨

江西永丰有省内最大的萤石矿资源地，为探讨该区萤石矿成矿地质条件与成因，进一步拓展资源潜力，助益矿产资源开发。通过近2 a对北坑、中富萤石矿进行储量核实工作，查明其成矿地质特征为：①萤石矿受NNE/NE向压扭性区域断裂构造控制，并产出于变质岩系地层与燕山早期花岗岩接触带部位。②矿区岩浆岩为过铝质高钾钙碱性 钾玄系。③矿石化学成分中CaF2和SiO2的含量变化具明显的消长关系，说明了成矿后的强烈硅化作用贫化了矿石中的CaF2含量。结合武夷山一带研究认为其成因为大气降水与岩浆混合热液在构造应力下激活运移，从变质岩及岩浆岩围岩中淋滤萃取易溶组分F、Ca、Si等，沿断裂构造有利部位沉淀富集成矿，形成中低温热液充填型脉状萤石矿床。

The Metallogenic Signature and Genesis Discussion of Fluorite Deposits in Yongfeng Area,Jiangxi

Yongfeng area is where the largest fluorite deposit located in Jiangxi province,in order to study the geological signatures and genesis of the fluorite for further development of resource potential,recent reserves verification on the two fluorite deposits in this area,revealed the metallogenic signature as below:①ore body is strongly constrained by NNE/NE fault structures,growth in the contact "spot" between metamorphic basement rocks of Nanhuan System and granite of Yanshan Period.②The rock type is high K calc alkaline adakite.③The relationship of enrichment and depletion between CaF2 and SiO2 are opposite,thus indicate a quantitative depletion of CaF2 due to silicification post mineralization.Resembling remarkably the ore genesis in Mt Wuyi area,metallogenic material such as F,Ca,Si,were offered prime opportunity by both metamorphic and magmatic wall rocks.Hydrothermal fluids,which consist of atmospheric precipitation in an infiltrated downward process plus magma,then heated and initiated upwelling by tectonic stress,in terms of extraction and strainer within wall rock.Finally,precipitation and enrichment along with favorable position in fault structures,allow fluorite deposits of low temp hydrothermal filling type been formed.