矿产预测中区域化探异常的识别和评价  

Recognition and Evaluation of Geochemical Anomaly in Regional Geochemical Quantitative Prediction

作　　者：龚鹏[1] 马振东[2] 

机构地区：[1]中国地质大学信息工程学院,湖北武汉430074 [2]中国地质大学地球科学学院,湖北武汉430074

出　　处：《地球科学（中国地质大学学报）》2013年第S1期113-125,共13页Earth Science-Journal of China University of Geosciences

基　　金：全国矿产资源评价子课题"矿产资源地球化学模型建立与定量预测研究"(No.1212010733805)

摘　　要：找矿模型建立、异常识别和异常评价是矿产预测中的3个主要环节,仅从地球化学异常识别和评价的视角进行探讨.首先,讨论了衬值异常、比值异常识别的方法和应用效果;其次,阐述了规格化面金属量、相似系数、剥蚀系数等3个评价参数的定义、内涵和计算方法,并用实例论述了其应用价值.实践表明,衬值能够有效识别弱缓异常,优选的元素对(组合)比值可以识别不同矿化类型和同一矿化类型成矿元素的主次;而重新厘定的规格化面金属量是示踪典型矿床主成矿元素和伴生元素的重要参数之一,相似系数和剥蚀系数分别是评价"观测样本"(预测区)与"标淮样本"(典型矿床)相似程度和剥蚀程度的重要指标.总之,无论是异常识别还是异常评价,其关键在于元素组合选取的合理性和遵循成岩-成矿-成晕同系统性以及多参数联合示踪的指导原则.Establishment of prospecting model,recognition and evaluation of geochemical anomaly are three key links in mineral prediction.This study concentrates on recognition and evaluation of geochemical anomaly.Firstly,the key technologies and recognition effect of contrast value and ratio value have been fully discussed for geochemical anomaly;secondly,the definition,connotation,and computational method of three geochemical parameters(i.e.normalized areal productivity(abbr.NAP),similarity coefficient,and denudation coefficient)have been elaborated,moreover several examples have been illustrated application value.Practice has proved that contrast value can identify weak geochemical anomaly and ratio value of appropriate element pair(association)can recognition different mineralization types;while redefined NAPis an effective parameter to trace main ore-forming elements and accompaniment elements for typical deposits,as well as similarity coefficient and denudation coefficient which are two crucial parameters being used to evaluate the extent of similarity and denudation between 'observation sample'(forecast area)and 'standard sample'(known deposit).In sum,both anomaly recognition and anomaly evaluation are based on reasonable election of element association and should be regarded as one system(diagenesis,metallogenesis,and geochemical halo)combined with multiparameter tracer.

关 键 词：区域化探 异常识别 规格化面金属量 相似系数 剥蚀系数 地球化学 

分 类 号：P632[天文地球—地质矿产勘探]