内蒙古多伦义盛店铀银多金属矿地质特征及控矿因素分析

摘要

多伦义盛店铀银多金属矿位于沽源—多伦铀多金属成矿带的北段，矿体赋存于上侏罗统满克头鄂博组三段蚀变钾长流纹岩和满克头鄂博组次流纹岩体内的隐爆角砾岩中。银矿体呈脉状产出，铀矿体呈似层状产出，受角砾岩带控制明显，属低硫型浅成低温热液矿床。结合前人研究成果，通过对银铀矿成矿地质特征、矿体定位及分布规律的分析研究，认为区内矿化与硅化、萤石化、菱锰矿化、水云母化和碳酸盐化等关系密切，矿化受火山—次火山岩体和 NW-NWW 向断裂带控制。NW-NWW 向构造角砾岩带是银多金属矿的有利储存空间；NW-NNW 向构造角砾岩带、次火山岩接触带及隐爆角砾岩带叠加复合部位是银铀多金属矿的最佳赋存部位。因此，构造角砾岩带、次火山岩接触带和隐爆角砾岩带可作为区内地质标志，结合地球化学异常和地球物理异常，指导区内找矿工作。%Duolun Yishengdian uranium-silver polymetallic deposit is located at the north of Guyuan-Duolun polymetallic metallogenic belt,which is a low sulfide,epithermal deposit,orebodies of this deposit are hosted in alteration potash-liparite of the third stage of Maotouebo in Jurassic and liparite of Mantouebo period,silver orebodies are veined,uranium orebodies are platelike,both are controlled by breccia zone.Combined to the study about geological character,orebodies,positon and distribution law of uranium-silver deposit,we state that alterations are closely related to silicification,fluorite,rhodochrosite,hydromica,carbonatation,which are controlled by volcanic,secondary volcanic and NW-NWW fault belt.NW-NWW pressure breccia belt is the profitable position of silver polymetallic deposit,the overlapped part of NW-NWW pressure breccia belt,secondary volcanic contact zone and hydrothermal breccia is the perfect zone for uranium-silver polymetallic deposit.Therefore,pressure breccia belt, secondary volcanic contact zone and hydrothermal breccia can be the geological symbol and help prospecting in the exploration area combined with geochemical anomaly and geophysical anomaly.