识别斑岩铜矿综合地球化学异常的光谱角方法  

Spectral Angle Method for Identification Integrated Geochemical Anomalies in Porphyry Copper Deposits

作　　者：陈松林 陈曦 王成彬[3,4] 胡飞 方臣 熊前进 杜翌超 Chen Songlin;Chen Xi;Wang Chengbin;Hu Fei;Chen Fang;Xiong Qianjin;Du Yichao(Hubei Administrative Center of Geological Exploration Funds,Wuhan,Hubei 430071;Hubei Geological Survey,Wuhan,Hubei 430034;State Key Laboratory of Geological Processes and Mineral Resources,China University of Geosciences,Wuhan,Hubei 430074;Faculty of Earth Resources,China University of Geosciences,Wuhan,Hubei 430074)

机构地区：[1]湖北省地质勘查基金管理中心,湖北武汉430071 [2]湖北省地质调查院,湖北武汉430034 [3]地质过程与矿产资源国家重点实验室,湖北武汉430074 [4]中国地质大学(武汉)资源学院,湖北武汉430074

出　　处：《资源环境与工程》2019年第2期241-246,共6页Resources Environment & Engineering

基　　金：湖北省地质局科技项目——多元遥感数据协同地质灾害遥感调查关键技术研究(编号KJ 2016—1),高光谱遥感响应地球化学异常信息提取机理研究——以恩施特农业区为例(编号KJ 2018—9),基于RS、GIS的自然资源评价及监测技术方法研究(编号KJ 2019—25);湖北省地质局地勘项目——湖北省自然资源遥感调查

摘　　要：介绍用光谱角法结合矿床指示元素和地质环境指示元素(氧化物),提取地球化学异常的方法。该方法是一种物理光谱分类方法,用于确定未知样品和已知参照物之间的相似性。光谱角分类是基于与斑岩铜矿有关的Al2O3、CaO、Co、Cr、Cu、Mg、Ni、Sn、Sr、Th、Ti、U、V、W、Y、Zn和Zr的地球化学“光谱曲线”差异。利用分形模型的对数图对光谱角阈值进行优化,得到最优分类。“光谱曲线”的拐点表明0. 2是分离地球化学数据和提取地球化学异常的最佳光谱角度阈值。填图结果不仅勾勒出土屋铜矿和延东铜矿地质背景异常,而且可以预测志留系侵入区的新铜矿化带。In this paper,spectral angle method (SAM),a physically-based spectral classification that determines the similarity between unknown test samples and endmember references,is introduced to extract geochemical anomalies by combining the indicator elements for ore deposits and geological environment indicator elements (oxides).The SAM classification is based on the geochemical“spectral curves” differences in Al 2 O 3 ,CaO,Co,Cr,Cu,Mg,Ni,Sn,Sr,Th,Ti,U,V,W,Y,Zn and Zr associated with porphyry copper deposits .The logarithm plot of fractal model is used to optimize the spectral angle threshold to obtain the optimum classification.The inflection point in the log-log plot indicates 0.2 is best optimum spectral angle threshold to separate the geochemical data and extract geochemical anomalies.The result mapping not only delineates anomalies that have a similar geological setting with Tuwu and Yandong copper,but also may predict a new copper mineralization zone in the area of Silurian strata with intrusion.

关 键 词：光谱角法 双对数图 地球化学异常 斑岩铜矿 

分 类 号：P632[天文地球—地质矿产勘探] TP75[天文地球—地质学]