内蒙古林西地区小北沟萤石矿床地质特征及找矿潜力分析

Features and potential analysis of Xiaobeigou fluorite deposit in Linxi,Inner Mongolia

在野外地质工作基础上,对小北沟萤石矿床的成矿地质背景、矿床地质特征、浅覆盖区的甚低频电磁异常、找矿潜力等进行了分析和探讨。研究表明:区内共发现矿(化)体11个,规模不一,主要受SN-NNE向断裂控制;矿石组分以萤石和石英为主,围岩蚀变主要发育硅化、高岭土化和绿泥石化;矿床为热液充填脉型,矿(化)体垂向分带特征明显,脉体形态、矿化强度、矿物组合以及矿石组构等特征自上而下呈现规律性变化;甚低频电磁异常显示Ⅶ号矿化体延续性好,规模可观。结合目前部分平硐和钻孔工程揭露的萤石矿体特征认为,本区深部找矿潜力大,Ⅶ号矿化体的深部工程验证应为后期工作的重点。

Based on geological field investigation, we present the metallogenic background, detailed geological characters of Xiaobeigou deposit, and geophysical anomalies delineated by the very low frequency electromagnetic method（ VLF-EM） and to discuss the prospecting potential with these data. So far, eleven fluorite orebodies （including mineralized bodied） with different scales and shapes have been found, which are strictly controlled by SN - NNE structures. The ore minerals are dominated by fluorite and quartz. Silicification, kaolinization and chloritization alteration spread in the wall rock. Xiaobeigou fluorite deposit is of hydrothermal-filled vein type. Vertical zoning of orebodies are observed, and characterized by regular variations of the vein shapes, mineralization degree, ore fabric and mineral assemblage from the top down. The VLF-EM survey under shallow overlay shows that No. YU mineralization body with good continuity is the largest in the area. Combined with mineralization characteristics of fluorite orebody revealed by the drift and drilling engineering, we conclude that this area has considerable prospecting potential at depth. And our priorities in the following project should focus on the depth of No. YU mineralization ore body.