基于证据权模型的厄立特里亚金矿资源潜力评价  

Quantitative evaluation of Eritrea gold resources potential based on the weight of evidence model

作　　者：刘江涛[1] 吴发富[1] 李福林[1] 胡鹏[1] 王建雄[1] 向文帅[1] 张紫程 LIU Jiangtao;WU Fafu;LI Fuling;HU Peng;WANG Jianxiong;XIANG Wenshuai;ZHANG Zicheng(Wuhan Center,China Geological Survey,Wuhan,430205;China Geological Mining Company Ltd,Beijing,100029)

机构地区：[1]中国地质调查局武汉地质调查中心,武汉430205 [2]中国地质矿业有限公司,北京100029

出　　处：《地质学报》2021年第4期1292-1305,共14页Acta Geologica Sinica

基　　金：中国地质调查局项目“北部非洲大型铜金资源基地评价”(DD20190443)资助的成果。

摘　　要：本文从控制热液运输通道的断裂密度、代表成矿物质来源的地球化学因子(异常,背景)、反映成矿围岩构成的卫星重力分布三个(共四个证据)对金矿具有显著指示意义的找矿指标入手,通过与现有已发现的金矿床进行比对检验后得到最佳的找矿证据。应用证据权模型,首次评估了厄立特里亚全国范围内不同区域发现金矿床的概率。依据计算得到的后验概率结果,在10%,30%及65%三个概率区间分别估计了未发现金矿床个数。结合北部非洲金矿床的吨位品位分布模型,估计得到了在三个概率区间下的厄立特里亚金矿的国家储量和资源量。按照发现金矿概率由高到低,在工作区划分了3级找矿有利区。结果显示,厄立特里亚具有良好的金矿的找矿潜力,除传统的北北东向与北北西向金矿成矿带外,两者的北方结合部位及其南部连通区域需要重点关注。通过与传统野外地质踏勘得到的厄特现有的成矿区带对比表明,本次划分的找矿远景不仅包含了传统的金矿成矿带,且在厄特南部发现了之前并未引起关注的带状区域,为厄特金矿找矿提供了新的探索方向。多方证据也表明,两条成矿带的结合部,也值得更多的关注。与其他方法得到的厄立特里亚的金矿储量资源量数据相比,本次估算结果首次给出了厄特特里亚金矿在不同概率空间下的储量资源量结果,对进一步摸清厄特的金矿潜力提供了更加精准的数据支撑。In this paper,three aspects(a total of four evidences)of controlling the fracture density of the hydrothermal transport channel,determining the source of ore-forming geochemical factors(anomalies,background),and reflecting the satellite gravity distribution of ore-forming surrounding rocks are significant for gold deposits.Starting with indicative prospecting indicators,the best prospecting evidence is obtained after testing with existing gold deposits,and for the first time,the weight of evidence model is used to calculate the posterior probability of gold metallogenesis across the country.The number of undiscovered gold deposits is estimated in the three probability intervals of 10%,30%and 65%.Combined with the tonnage-grade model of gold deposits in North Africa,the national reserves and resources of Eritrea gold mines are estimated in three intervals.Based on the calculated posterior probability distribution,three-level favorable prospecting areas are divided according to the probability of finding gold deposits from high to low.The results show that Eritrea has good prospecting potential for gold deposits.Except for the traditional NNE and NNW trending gold metallogenic belts,the northern junction of the two and the southern interconnection area need to be paid attention to.The comparison with the existing metallogenic belts of Eritrea from traditional field geological surveys shows that the prospecting prospects of this division not only include the traditional gold metallogenic belts,but also found in the southern part that have not attracted attention before.The belt-shaped area provides a new direction for exploration in the Eritrea gold deposits.Various evidences also show that the junction of the two metallogenic belts also deserves more attention.Compared with Eritrea’s gold reserves and resources data obtained by other methods,this estimation result provides the results of Eritrea’s gold reserves and resources in different probability spaces for the first time,which provides more accurate data su

关 键 词：资源潜力 定量评价 证据权 厄立特里亚金矿 

分 类 号：P618.51[天文地球—矿床学]