【作者】 张船红；

【导师】 何政伟；

【作者基本信息】 成都理工大学 ， 地图制图学与地理信息工程， 2011， 硕士

【摘要】 研究区位于西藏自治区中南部的墨竹工卡地区,区内包括两大已知矿床——驱龙、甲马。西藏墨竹工卡地区属高山深切割地区,海拔高、坡度大,对于大面积的找矿工作较为艰难,运用遥感手段研究已知矿区的遥感找矿信息是非常必要的,从而更加宏观的把握好找矿区域信息,并能为其他找矿手段提供有效的辅助作用。在研究区提取的遥感找矿蚀变信息和解译的线环构造信息基础上,结合地层岩性、地球化学、地球物理等资料进行找矿信息的综合分析,验证了以遥感找矿信息为主,其他信息为辅,互相辅助结合对找矿工作的重要性和有效性。论文选用ETM+影像和ASTER影像作为遥感数据源,结合前人研究成果,对找矿蚀变信息提取理论进行研究,分析ETM+和ASTER影像波谱特征,然后进行图像预处理、去干扰异常处理,最后运用比值法、主成分分析法进行遥感找矿蚀变信息提取。对不同数据源提取的蚀变信息结果进行空间叠加分析,定量化的分析叠加蚀变信息,从而确定基于不同数据源、不同蚀变信息提取方法的综合蚀变异常信息。对ETM+影像进行波段相关性分析,得出ETM+741为最佳波段组合,对ETM7、ETM4、ETM1波段进行RGB彩色合成,得到遥感影像线环构造解译的底图。建立研究区的线性构造和环形构造的解译标志,分别进行构造解译,得到线环构造解译图,并进行线性构造方位分析,线性构造、环形构造的密度分析。环形构造与线性构造都不是独立的地质构造现象,它们呈现不同组合形式的分布,分析线-线构造集中区、环-环构造集中区以及线-环构造集中区,从而确定出找矿的有利部位,来验证遥感线环构造与区内矿产的生成具有一定的内在联系。将研究区提取的遥感蚀变信息分别与地层岩性、地球物理、地球化学信息进行复合叠加研究,均呈现了较好的正相关性,进一步证明了文中提取出的遥感蚀变信息的可靠性、有效性。最后分别对驱龙矿区和甲马矿区的找矿信息进行综合分析,结果表明:矿区内遥感蚀变异常、线环构造与地层岩性、地球化学等数据信息的呈现高度正相关性,从而验证了遥感蚀变信息与线环构造信息作为找矿信息的有效性。运用遥感和GIS方法,改善遥感蚀变信息提取方法和流程,加强遥感构造解译程度,进一步提高遥感蚀变信息和遥感线环构造在找矿工作的有效性,从而进行多元找矿信息综合分析,以达到更为准确的定位找矿区域是论文进一步研究的重点。更多还原

【Abstract】 Studying area is Mozhugongka region, which is located in the south-central of the Tibet and includs the two known deposits——Qulong porphyry copper deposit and Jiama copper-polymetallic deposit. Studying area is a alpine areas of deep cuts, high elevation and steep slope, so it is more difficult for large areas of prospecting work. From this perspective, it is essential to study the remote sensing ore-finding information of the known areas using remote sensing means, thereby further grasping the prospecting information from the macroscopic and providing effective aids for other prospecting method. Based on the remote sensing prospecting alteration and interpreted of linear structure and ring structure information extracted from the studying areas and combining lithology, geochemical and geophysical prospecting data from a comprehensive analysis of information, the method, which gives priority to prospecting information based on remote sensing and is supplemented by other information, proved to be important and effective.ETM+ image and ASTER images were used as remote sensing data sources. Firstly, with previous research results, researches on the prospecting alteration information extraction theory and analysis of the spectral characteristics of ETM+ and ASTER data were done; secondly, preprocess the images and remove the interferences; finally, extract the remote sensing prospecting alteration information by using the ratio method or the principal component analysis. Using spatial overlay analysis for the result of alteration information from different data sources extracted, quantitative analysis of space superposition alteration information, then the comprehensive altered anomaly information was got based on different data sources and method of alteration information extraction.With the spectral band characteristics of ETM+ image, by doing relevant analysis of band, to get ETM7\ETM4\ETM1 band to RGB combination, then uses this image to do visual interpretation of geological structure. Remote sensing signs of structural interpretation in the studying area are established, and interpreted linear structure and ring structure, and obtained the geological structure interpretation graph, then orientation analysis of linear structure, density analysis of linear structure and ring structure. Linear structure and ring structure are not the independent geological structure phenomenon, they appeared with different combination forms, so, Through analysis the linear structure concentration area, the ring structure concentration area, and the linear-ring structure concentration area, thus determine the favorable ore-prospecting area, finally, to verify remote sensing linear-ring structures has a certain internal relations with the mineral in the studying area.The results, made by compositely overlaying the remote sensing alteration information extracted from the studying areas with the formation lithology, geochemical and geophysical information, showed a good positive correlation, so the remote sensing alteration information extracted in this paper proved to be reliable and efficient. At last, An comprehensive analysis of prospecting information for Qulong and Jiama mining area was made and the results showed that: In the mining areas, remote sensing alteration information, linear-ring structure and formation lithology, geochemical data prospecting information appeared to be highly positive-correlated, which verified the validity of the remote sensing alteration information and linear-ring geological structure as prospecting information.In order to locate the prospecting areas more accurately, the emphasis is that: improving the remote sensing anomaly extraction methods and processes with RS and GIS, strengthening the interpretation of the extent of remote sensing geological structure to further improve the efficiency of remote sensing alteration information and linear-ring structure in prospecting work and thereby comprehensively analyzing the multivariate prospecting information.更多还原