基于元素含量和空间变异系数的化探异常信息识别  

Identifying geochemical anomalies according to the content and coefficient variance of trance elements

作　　者：周曙光[1,2,3,4] 周可法[1,3] 崔遥[1,3] 王金林[1,3] 丁建丽[2] 

机构地区：[1]中国科学院新疆生态与地理研究所新疆矿产资源研究中心,乌鲁木齐830011 [2]新疆大学资源与环境科学学院,乌鲁木齐830046 [3]新疆矿产资源与数字地质实验室,乌鲁木齐830011 [4]中国科学院大学,北京100049

出　　处：《地质科学》2015年第3期1014-1022,共9页Chinese Journal of Geology(Scientia Geologica Sinica)

基　　金：国家自然科学基金项目（编号：U1129302）、新疆维吾尔自治区青年科技创新人才培养工程项目（编号：2013731014）、国家重点基础研究发展计划“973”项目（编号：2014CB440803）、新疆维吾尔自治区重大专项（编号：201330121-2,201330121-3）和科技支撑计划项目（编号：2012BAH27805.06）资助.

摘　　要：化探异常信息识别是化探数据分析最重要的任务之一，也是化探数据在资源勘查领域受到广泛关注的最重要原因，前人对化探异常信息识别做过大量研究，这些研究中的大多数主要关注化探示踪元素的含量，近而根据含量指标计算异常阈值，而对示踪元素在空间中的分布特征关注较少。本文选择1：20万比例尺的克拉玛依幅为研究区，根据区内金矿的矿床地球化学特征选择Ag、As、Au和Sb等4种元素为本区内金矿的示踪元素，以地球化学元素分散晕形成理论为依据，使用GIS技术和Matlab软件绘制研究区内4种金矿示踪元素的综合地球化学异常图。结果表明，与传统阈值方法得到的化探异常图相比，本文得到的化探异常图能够更好地指示研究区内已知金矿。Identifying of geochemical anomalies from geochemical data is one of the most important tasks, and which is the reason why it is get extensive attention in the field of mineral resource exploration. Most of the geochemical anomaly identification methods pay more attention to the calculation of anomaly threshold, however, there is no one method which is widely accepted yet. To get more reliable and reasonable geochemical anomalies from geochemical data, the 1：200 000 geochemical exploration data, which comes from Karamay area, at the west of Zungar, Xinjiang, are selected to identify geochemical anomalies. The data are mainly collected from stream sediment, and the content of 39 elements are determined from every sample. In this study, silver （Ag） , arsenic （As） , gold （Au） and antimony （Sb） are selected as trace elements of gold deposits. ArcGIS software package is used to produce the raster maps of Ag, As, Au and Sb, then Matlab software package is used to get the coefficient variance maps of Ag, As, Au and Sb with window-based method based on the four raster maps. The synthetic anomaly maps of Ag, As, Au and Sb are produced according to their content and coefficient variance, then the synthetic anomaly maps are compared with the anomaly maps from conventional method. The result shows that the synthetic anomalies can indicate the known gold deposits in this area more clearly than conventional method. The synthetic geochemical anomalies are more reasonable and interpretable according to the theory of the formation of dispersion halo bf geochemical element. At last, principal component analysis technique is used to get the multi-element geochemical anomaly map. The multi-element geochemical anomaly map can be helpful for further exploration task in this area, and the technique in this study may be explored and used in other places.

关 键 词：地球化学异常 变异系数 示踪元素 

分 类 号：P588[天文地球—岩石学]