基于矿点捕获效率的赣南地区钨勘查地球化学异常多准则识别与提取

Multi-criteria identification and extraction of tungsten-related exploratory geochemical anomalies in southern Jiangxi Province based on capturing efficiency of mineral occurrence

赣南地区的黑钨矿资源是重要的战略性有色金属资源,钨矿化相关地球化学异常的识别和提取对钨资源的勘查具有重要的指示意义。本研究通过聚类分析与主成分分析,识别出与赣南钨矿化密切相关的8种单元素(Ag、Cd、Pb、Bi、W、Cu、Sn、As)和元素组合(Ag、Bi、Cd、Cu、F、Pb、Sn、W、Zn、As);采用累计频率法、浓度-面积(C-A)模型和预测-面积(P-A)模型提取地球化学异常,通过捕获效率定量评估上述3种方法圈定的异常区域并进行对比分析。结果表明,8种单元素和元素组合的高异常区分布与区内4个矿集区相对应,表现出良好的指示作用。在累计频率法和C-A模型中,主成分2综合异常的捕获效率均最高(4.39和33.90),分别在15.04%的区域中识别出66.10%的矿点,以及在0.10%的区域中识别出3.39%的矿点;在P-A模型划分的异常区域中W元素的捕获效率最高(3.17),在23.97%的区域中识别出76.03%的矿点。对比3种方法,C-A模型的异常区域展示了最高的矿点捕获效率(33.90),但所圈定的矿点数量相对较少;P-A模型的异常区域矿点捕获效率虽然较低,但识别出最多的矿点(76.03%),展现出更高的捕获矿点覆盖率。本研究综合考虑矿点捕获效率和捕获矿点覆盖率,选择基于多准则提取的主成分2和W元素地球化学异常评价区域成矿潜力,并绘制异常分布图。

The tungsten(W)resources in southern Jiangxi Province represent important strategic non-ferrous metals resources.The identification and extraction of tungsten mineralization-related geochemical anomalies play a crucial role in tungsten prospecting.This article identifies eight single elements(Ag,Cd,Pb,Bi,W,Cu,Sn and As)and element associations(Ag,Bi,Cd,Cu,F,Pb,Sn,W,Zn and As)that are closely related to tungsten mineralization in southern Jiangxi Province through cluster analysis and principal component analysis.The cumulative frequency method,concentration-area(C-A)model,and prediction-area(P-A)model were utilized to extract geochemical anomalies,and quantitatively evaluate the anomalous areas delineated by the above three methods through capturing efficiency and conducting comparative analysis.The research results indicate that the distribution of high anomalies for these eight single elements and element association corresponds to the four ore districts within the area,demonstrating a strong indicative effect.In both the cumulative frequency method and the C-A model,the capturing efficiency of principal component 2 is the highest(4.39 and 33.90),with 66.10%of mineral occurrences identified in 15.04%of the area and 3.39%identified in 0.10%of the area,respectively.The P-A model has the highest capturing efficiency of the W element in the anomalous area(3.17),identifying 76.03%of the mining occurrences in 23.97%of the area.Among the comparison of these three methods,the C-A model exhibits the highest capturing efficiency of mineral occurrence in anomalous areas(33.90).However,the number of delineated mineral occurrences was relatively small.Although the P-A model has a lower capturing efficiency of mineral occurrence in anomalous areas,it identifies the most mineral occurrences(76.03%),demonstrating a higher coverage of captured mineral occurrence.Therefore,this article comprehensively considers the capturing efficiency of mineral occurrence and coverage of captured mineral occurrence,and selects principal component 2 and W element geochemical anomalies based on multi-criteria extraction to evaluate the regional mineralization potential,and finally produces the anomaly distribution map.