湖南省桃源县沅水以南地区土壤地球化学特征及找矿预测

Soil Geochemical Characteristics and Mineral Exploration Prediction in the Area South of the Yuanshui River in Taoyuan County, Hunan Province

摘要: 桃源县沅水以南地区位于雪峰弧形构造隆起带中段转折部位，成矿地质条件优越。通过研究区1:50000土壤地球化学数据多元统计分析，发现Au、Hg、Sb、W具有较强的找矿潜力。运用含量—面积分形方法确定Au、Hg、Sb、W异常下限值分别为40 ng/g、1 μg/g、10 μg/g、20 μg/g。单元素异常和组合异常分析显示，研究区金矿有两种类型，一种是冷家溪型金矿，主要特征是以Au异常为主，Hg、Sb异常吻合度高，为前缘晕指示元素组合，W异常弱，矿产类型以金矿为主。另一种是西安型金矿，主要特征是以W异常为主，Au异常中等，Hg、Sb异常弱，矿产类型以钨矿为主，金矿为辅。通过分析西安钨金矿区、冷家溪金矿区矿床地质特征，总结成矿富集规律，圈定了3个找矿靶区，实证显示雷打岭附近致矿异常较好，具备较强的找矿潜力。

Abstract: The area south of Yuanshui in Taoyuan County is located at the turning point of the Xuefeng arc-shaped structural uplift belt, with superior ore-forming geological conditions. Through multivariate statistical analysis of 1:50000 soil geochemical data in the study area, it was found that Au, Hg, Sb, and W have strong prospecting potential. Using the content area fractal method to determine the lower limit values of Au, Hg, Sb, and W anomalies as 40 ng/g and 1, respectively μg/g, 10 μg/g, 20 μg/g. The analysis of single element anomalies and combination anomalies shows that there are two types of gold deposits in the study area. One is the Lengjiaxi type gold deposit, which is mainly characterized by Au anomalies, high consistency of Hg and Sb anomalies, and a combination of leading edge halo indicator elements. The W anomaly is weak, and the mineral type is mainly gold deposits. Another type is the Xi’an type gold deposit, which is mainly characterized by W anomalies, moderate Au anomalies, weak Hg and Sb anomalies, with tungsten deposits as the main mineral type and gold deposits as auxiliary. By analyzing the geological characteristics of the tungsten gold deposit in Xi’an and the Lengjiaxi gold deposit, summarizing the ore-forming enrichment laws, and delineating three prospecting target areas, empirical evidence shows that the ore-forming anomalies near Leidaling are good and have strong prospecting potential.