Pb-S-Hg-Cu同位素在覆盖区找矿勘查中的应用与前景  

Applications and prospects of Pb-S-Hg-Cu isotopes in mineral exploration in covered areas

作　　者：盘炜 刘雪敏 鲁岳鑫 PAN Wei;LIU Xuemin;LU Yuexin(Applied Nuclear Techniques in Geosciences Key Laboratory of Sichuan Province(Chengdu University ofTechnology),Chengdu 610059,China;Key Laboratory of Geochemical Exploration of Ministry of Natural Resources,Institute of Geophysical and Geochemical Exploration,Langfang 065000,China)

机构地区：[1]地学核技术四川省重点实验室(成都理工大学),成都610059 [2]中国地质科学院地球物理地球化学勘查研究所自然资源部地球化学探测重点实验室,河北廊坊065000

出　　处：《成都理工大学学报(自然科学版)》2025年第2期236-252,共17页Journal of Chengdu University of Technology: Science & Technology Edition

基　　金：国家重点研发计划(2016YFC0600604);国家自然科学基金(4160030199)。

摘　　要：深部的隐伏矿体不论被基岩还是碎屑物覆盖,都能在地表介质中形成弱地球化学异常。但其他地质过程和人类活动也可以形成类似异常,所以判断地表圈定的弱地球化学异常是否由深部隐伏矿体引起,是未来深穿透地球化学方法在未知覆盖区广泛应用的关键。同位素可以有效示踪地表地球化学含矿异常的来源,在隐伏矿勘查中具有广阔的应用前景。本文综述了传统的Pb,S同位素和非传统的Hg,Cu同位素在隐伏矿勘查中的应用原理,聚焦于地气、土壤、水、风化淋滤帽的同位素组成在覆盖区找矿勘查中的研究进展,分析了该领域目前存在的主要问题,并提出了应用建议。取得以下几点认识:首先,覆盖区地表介质中的同位素组成会因深部矿体的影响而存在系统的空间变化,从而指导深部隐伏矿体的勘查;第二,地下水和土壤是应用最广的2类地表介质,已知隐伏区各类介质的系统同位素组成研究,可为类似未知覆盖区最优采样介质的选择提供基础;此外,同位素存在分析成本高、体系选择和异常解释难的问题,制约了其在勘查地球化学领域的广泛应用。同位素更适合在矿产详查、老矿区深部和周边找矿中使用,在确保实验室分析技术成熟、实验经费可负担的前提下,优先选择相对质量差小、几乎不存在与质量有关的分馏的同位素。Concealed ore deposits,whether covered by bedrock or detritus,can generate weak geochemical anomalies in surface media.However,similar anomalies can also be formed by other geological processes and human activities.Therefore,it is crucial to determine whether weak geochemical anomalies on the surface are caused by concealed ore deposits,which is key to the wide application of deep-penetrating geochemical methods in unknown covered areas.Isotopes can effectively trace the source of surface geochemical anomalies containing ore-forming elements,and have broad application prospects in concealed ore exploration.This paper reviews the application principles of using the traditional Pb and S isotopes and nontraditional Hg and Cu isotopes in concealed ore exploration.We focus on the progress of research related to determining the isotopic compositions of soil gas,soil,water,and leach cap in covered area exploration,analyze the main problems present in this field,and propose application improvements.The following conclusions are drawn.First,the Pb-S-Hg-Cu isotopic composition in surface media exhibits systematic spatial variations due to the influence of deep ore bodies,which can guide the exploration of concealed ore deposits at depth.Second,groundwater and soil are the two most widely prevalent surface media.Previous studies of the systematic,isotopic composition of various media in concealed areas can provide a basis for selecting the optimal sampling medium in similar unknown covered areas.Third,isotope analysis has the problems of high analysis cost,difficulty in system selection,and anomaly interpretation,which restrict its wide application in exploration.Isotopes are more suitable for use in detailed mineral exploration,and deep exploration of old mining areas and surrounding areas.On the premise of ensuring that current analysis techniques and funding for experiments are sufficient,it is necessary to give priority to isotopes with little relative mass difference and mass-independent fractionation.

关 键 词：覆盖区找矿 PB同位素 Hg同位素 异常识别 

分 类 号：P632[天文地球—地质矿产勘探]