黑龙江省嫩江县二道坎村银多金属矿床地质特征及找矿标志

Geological characteristics of Erdaokancun Silver Polymetallic Deposit,Nenjiang County, Heilongjiang Province and its prospecting indicators

二道坎村银多金属矿床是黑龙江省首例独立银矿床,伴生铅锌锰等元素,其赋矿地层为顶志留统—中泥盆统泥鳅河组,矿体主要赋存在辉绿岩与泥鳅河组接触带的地层一侧。矿区内共圈定2条银多金属矿体,均呈脉状赋存于北西西向断裂构造带中;矿石中金属硫化物以黄铁矿为主,方铅矿、闪锌矿次之;银矿物以辉银矿为主,其次为深红银矿,少量脆银矿、自然银等;矿体围岩蚀变发育,主要有硅化、碳酸盐化、高岭土化、绢云母化、绿帘石化、绿泥石化、黄铁矿化,其中硅化、黄铁矿化、绢云母化与成矿关系密切。泥鳅河组地层、北西西向断裂构造、辉绿岩脉等是重要地质找矿标志,Ag、Pb、Zn元素土壤地球化学异常是重要的地球化学找矿标志。

Erdaokancun Silver Polymetallic Deposit is the first independent silver deposit of Heilongjiang Pro-vince.The deposit is associated with lead,zinc,manganese and other elements.The ore host strata is top Silurian-upper Devonian Niqiuhe Formation.The ore bodies mainly occur on the strata that is on the contact zone of diabase and Niqiuhe Formation.There are 2 silver polymetallic ore bodies delineated in the district,both occurring in NW fault in vein types;the metal sulfide are mostly pyrites,followed by galena and sphalerite;the silver minerals are mostly acanthite,followed by pyrargyrite and minor content of stephanite and native silver.Wall rock alteration develops in ore bodies,mainly including silicification,carbonatization,kaolinization,sericitization,epidotization,chloritization and pyritization.Among them,silicification,pyritization and sericitization are closely related to the mineralization.Strata in Niuqiuhe Formation,NWW fault,diabase vein are important geological prospecting indicators.Ag,Pb,Zn soil geochemical anomalies are important geochemical prospecting indicators.