【作者】 张廷斌；

【导师】 黄丁发；

【作者基本信息】 西南交通大学 ， 大地测量学与测量工程， 2013， 博士

【摘要】 自20世纪70年代Rowan等利用美国陆地卫星判别褐铁矿蚀变带以来,利用遥感技术提取与矿化有关的蚀变岩(矿物)得到了迅速的发展。当前,遥感技术已经贯穿于地质勘查的全过程。遥感蚀变信息提取和应用作为一个重要的发展方向,在地质矿产勘查领域发挥着不可或缺的作用。国内外遥感技术的快速发展,为地质矿产勘查提供了不同空间分辨率、不同光谱分辨率的遥感数据,极大地丰富了遥感地质勘查的信息。但与此同时,理论基础和应用基础研究不足或滞后已成为遥感技术进步和应用向纵深发展的障碍。遥感蚀变信息是基于遥感信息的物理机制和蚀变矿物的光谱特征,从遥感数据中提取的与围岩蚀变有关的遥感找矿信息。利用遥感技术提取斑岩型铜矿床的围岩蚀变信息具有快速、高效、低廉的优势,但是由于遥感蚀变信息提取受蚀变矿物组合、地表环境、遥感数据源、提取方法、表达方法等的影响,遥感信息的“重现”条件及“重现”规律,成为遥感蚀变信息能否推广应用的关键。本文以西藏典型斑岩型铜矿为例,通过定性与定量分析、原型与模型分析相结合的方法,在深入总结斑岩型铜矿床围岩蚀变的分带规律与蚀变矿物(组合)的波谱响应基础上,从不同提取尺度、不同定量化表达方法、不同遥感数据等方面,研究了遥感蚀变信息的“重现性”规律；初步建立了斑岩铜矿遥感蚀变信息的优选准则,发展了遥感地质信息的诠释模式。主要研究成果如下：1.针对遥感蚀变信息提取与分析中存在的诸多不确定性因素,提出了遥感蚀变信息重现性的概念。2.提出了遥感蚀变信息提取的尺度效应概念,并通过构建异常下限、异常面积、异常斑块数、异常密度、主分量信息熵和异常信息熵等参数进行了“E尺度效应”评价。多龙铜矿基于主成分分析的蚀变信息提取实验结果表明,尺度效应对遥感蚀变信息的提取具有重要的影响；遥感铁染异常的最优提取尺度约为典型矿床范围的5倍左右,而当提取尺度超过典型矿床的120倍时,遥感羟基异常的提取结果会发生异常类的变化。3.基于驱龙铜矿主成分分析提取的蚀变信息结果,通过对多种定量化表达方法的对比分析认为,分形分维法计算严密、稳定性强,是遥感蚀变信息的最优定量化表达方法。4.通过玉龙、驱龙和多龙典型矿床不同遥感数据源遥感蚀变信息结果的对比分析,提出了基于遥感数据的蚀变信息重现性概念；实验结果表明,数据源因素对蚀变信息的重现性具有一定的影响,但在时相差异不大的情况下,同传感器数据提取的遥感信息具有一定程度的可比性。5.从成矿地质条件、蚀变矿物成因和蚀变信息组构等三个方面入手,初步建立了斑岩铜矿遥感蚀变信息的优选条件。提出并定义了遥感蚀变信息组构的概念；基于斑岩铜矿蚀变分带的理论模型,分析了斑岩铜矿遥感蚀变信息组构分析的优选条件。更多还原

【Abstract】 Since Rowan discriminated the limonite alteration zone with Landsat image in the1970s, application of remote sensing mineralized alteration extraction has gained the rapid development. At present, remote sensing technology runs through the whole process of geological survey. As an important development direction, extraction and application of remote sensing mineralized alterations play important roles in the field of geological survey. With the rapid advancement of remote sensing technology at home and abroad, they can offer remote sensing data of different spatial resolution and spectral resolution and greatly enrich the information of geological survey. At the same time, the under-researched theoretical basis and application foundation have hindered the further development of remote sensing technology in depth and breadth.Based on the physical mechanisms of remote sensing and spectral features of altered minerals, remote sensing mineralized alterations, extracted from remote sensing data, refer to the remote sensing information related to wall rock alteration for mineral exploration. It has advantages of rapidness, efficiency and cost-effectiveness to make use of the remote sensing technology to extract the wall rock alterations of the porphyry copper deposits; however, because the mineralized alteration extraction from remote sensing data are influenced by many factors including the altered mineral combination, surface environment, remote sensing data source, extraction method, and expression method, the "repeatability" condition and "repeatability" mechanism of remote sensing mineralized alterations become the key factors of the application of remote sensing alterations.Taking typical porphyry copper deposits of wall rock of Tibet as example, this dissertation aims to explore the repeatability mechanism for remote sensing mineralized alterations with different extraction scales, quantitative expression methods and different data source based on a comprehensive summary of zoning rules of wall-rock alteration of porphyry copper deposit and spectrum responses of altered materials(combinations); it primarily establishes the evaluation criteria about screening, classification, and application principles.The main research results are listed as follows:1. As for the uncertain factors in the extraction and application of remote sensing mineralized alterations, this study puts forward the repeatability concept of remote sensing mineralized alterations. 2. It establishes the scale effect concept in the extraction of remote sensing mineralized alterations and evaluates the scale effect with parameters of anomaly threshold, anomaly plaque, anomaly density, principal component entropy, and anomaly entropy. Experimental results based on Duolong porphyry copper remote sensing anomaly of PCA (principal component analysis) show:scale effect has a significant influence on remote sensing mineralized alterations; the optimal extraction scale of ferric alteration is about5times of the typical deposit extent; and the results of hydroxy alteration will change the anomaly classes when the extraction scale exceeds120times of deposit extent.3. Experimental results based on Qulong porphyry copper remote sensing anomaly of PCA (principal component analysis) show that the fractal method is an optimal quantitative expression method because of its precise calculation and high stability through the comparative analysis of quantitive expression methods.4. It presents the concept of data repeatability in extraction of remote sensing mineralized alterations. Experiments of Yulong, Qulong and Duolong porphyry copper deposits show that remote sensing data have some certain influence on the repeatability in extraction of remote sensing mineralized alterations. In the unobvious differences of time phases, the results from the same sensor of remote sensing mineralized alterations have some degrees of comparability.5. From the aspects of mineralized geological condition, genetic mineralogy and fabric of remote sensing mineralized alterations, it initiates to establish optimal conditions of remote sensing mineralized alterations of porphyry copper deposit and promotes and defines the fabric analysis concept of remote sensing mineralized alteration; and then, on a basis of the theoretical model of hydrothermal alteration zone of porphyry copper deposit, it analyzes the optimal conditions of fabric analysis of remote sensing mineralized alterations.更多还原