青海泥巴山一带Sb地球化学特征及锑金矿找矿前景

摘要

青海泥巴山一带地处东昆南断裂以南的华南板块鲸鱼湖—阿尼玛卿晚古生代—早中生代缝合带.分析了青海泥巴山一带Sb等元素的地球化学分布富集特征,讨论了元素组合特点及相关性.对比分析了1 : 5万水系沉积物Sb异常和1 : 1万土壤地球化学Sb异常,认为Sb异常重现性好,且伴生有Au、Cu、Pb、Zn等元素组合,呈现水平分带现象,具有层控型Sb矿异常特点.结合区内化探成果,进行了异常工程验证,发现锑矿体1条(Sb品位为0.48% ~5.97%,平均3.23%)、金矿体1条(Au品位为1.2 g/t).研究表明:①昌马河组浊积岩为金锑矿的成矿母岩,断裂构造为岩浆和热液提供了良好的上升通道,从而严格控制着区内金锑矿(化)体的分布;②在该区采用1 : 5万水系沉积物测量→1 : 1万土壤地球化学测量→地质观察→槽探工程揭露的找矿方法效果较明显,1 : 1万土壤测量Sb异常大于20×10-6的地段均有可能发现锑矿(化)体.在上述分析的基础上,划分出了A、B、C 3个找矿靶区,并在A靶区经探槽揭露发现了锑金矿(化)体,显示出该靶区找矿前景较好.%Nibashan area of Qinghai Province is located in the suture belt of Late Paleozoic-Early Mesozoic named Jingyu Lake-A'nyemaqen of the South China plate that lied at the south of Dongkunnan fault.According to the analysis results of the enrichment characteristics of the element such as Sb etc.In Nibashan Area,Qinghai Province,the combination and correlation characteristics of the chemical element in the area are discussed.By the comparison analysis of the Sb element abnormity ob-tained by 1 : 50 000 stream sediment survey and 1 : 10 000 soil geochemcial survey,it is show that the reproducibility of Sb element abnormity is perfect,and accompanying the element combination of Au,Cu,Pb,Zn,etc.,the horizontal banding phe-nomenon of the element combination is appeared significantly,besides that,the element combination is also characterized by stratabound Sb element abnormity.Based on the above geochemical survey results of the area,the engineering verification of Sb element abnormity is done,and one antimony ore-body and one gold ore-body are found,the grade of antimony of the former from 0.48% to 5.97%,with the average grade of antimony is 3.23%,grade of gold of the later is 1.2 g/t.The study results indicated that:①turbidite of Changmahe Formation is the parent rock mass of Au-Sb deposit in the area,the favorable channels of magmatic and hydrothermal are provided by faults,therefore,the distribution of Au-Sb ore-body is controlled strictly by the rock mass and faults;②ideal prospecting results in the area can be obtained by using the integrated prospecting method of 1 :50 000 stream sediment survey,1 : 10 000 soil geochemcial survey,geochemical investigation and trenching engineering verifi-cation,and antimony ore-bodies might be found in these areas where the Sb content is higher than 20×10-6by using 1 : 10 000 soil geochemical survey method.Based on the above study results,three prospecting target areas (named A,B and C) are de-lineated,among them,Sb-Au ore-body(ore mineralized body) are found in the A prospecting target area by trending engineer-ing verification,which further indicated the prospecting potential of Au-Sb deposit of the area is good.