多光谱遥感技术预测矿产资源的潜能——以蒙古国欧玉陶勒盖铜金矿床为例

建议把蚀变遥感异常作为一个新的找矿参数,文中讨论了蚀变遥感异常的地质基础和光谱前提。在矿床地质学和蚀变矿物光谱参数特征的基础上,编制了一张用于蚀变遥感异常提取及对其地质解释的表格。设计了从ETM+和ASTER数据中提取羟基蚀变矿物组合信息的独特流程方案。这个方案称之为"去干扰异常主分量门限化技术",文中示以简化的流程图。ETM+数据用来研究位于欧玉陶勒盖铜金矿床东北部的汉保各德中酸性火成杂岩体岩性特征,ASTER近红外和短波红外数据用来提取欧玉陶勒盖斑岩铜金矿矿床及其近区的羟基异常,通过选择性主分量分析判断欧玉陶勒盖铜金矿矿床的矿床类型为斑岩型。已知矿区各矿体的羟基异常都十分清晰,此外在矿床西部还发现了三个新的有希望的羟基异常。此工作进一步展示出多光谱遥感技术对于金属矿床的预测具有极好的潜能。

The potential of multi-spectral remote sensing techniques for mineral exploration-taking the Mongolian Oyu Tolgoi Cu-Au deposit as an example

In this paper,we propose a new parameter-alteration remote sensing anomalies for predicting mineral resources.The geological basis and the spectral features for alteration anomalies are discussed.Based on the deposit geology and spectral characteristics of alteration minerals,we have constructed a table of remote sensing alteration anomalies and related geological interpretations.We have developed an advanced system for the identification of hydrothermal alteration assemblages using ETM+(Enhanced Thematic Mapper)and ASTER(Advanced Space-borne Thermal Emission and Reflection radiometer)data,which is called the "De-interfered Anomalous Principal Component Thresholding Technique".In this paper,a simplified flow chart of this system is provided,in which the five main blocks of the system are illustrated.These five main blocks are:preprocessing,sub-normalization,anomaly-identification,post-processing and thresholding.The ETM+ data were used for studying lithologic characteristics of the Hanbogd igneous complex of intermediate-felsic rocks in the northeast of Oyu Tolgoi Cu-Au deposit.The ASTER VNIR and SWIR data were used to identify hydroxyl anomalies for Oyu Tolgoi Cu-Au deposit and nearby areas.The Oyu Tolgoi Cu-Au deposit is recognized as a porphyry system by the selective principal component analysis of ASTER data.The hydroxyl anomalies for all known ore bodies are well displayed;in addition,three new prospective hydroxyl anomalies were discovered to the west of the deposit.This work demonstrates that multi-spectral remote sensing techniques have excellent potentials for the prospecting of metallic minerals.