陆地卫星TM及JERS-1卫星SAR数据用于西藏东部斑岩铜矿勘查

EXPLORATION FOR PORPHYRY COPPER DEPOSITS WITH LANDSAT TM AND JERS-1 SAR DATA IN THE EASTERN TIBET CHINA

本文介绍了利用陆地卫星ＴＭ及ＪＥＲＳ－１卫星ＳＡＲ数据在西藏东部地区进行斑岩铜矿勘查项目的早期研究成果。文中通过对现有地质资料的分析认为，研究区内的矿化作用除受三叠系火山岩建造控制外，还与喜山期的中酸性侵入体有关。而陆地卫星ＴＭ图像的解译结果表明，区内的主要矿床几乎都分布在与三叠纪古火山机构相关的环形构造内。为了增强和提取出与斑岩铜矿化有关的蚀变岩信息，研究中采用了对数残差、矿物指数和ＨＳＩ变换等方法对陆地卫星ＴＭ及ＪＥＲＳ－１卫星ＳＡＲ数据进行了处理与分析，所提取出的蚀变信息与目视解译所发现的环形构造位置极为吻合。实践证明。

Some preliminary results for the study project are described in this paper, for which the remotely sensed data such as the Landsat TM image is used into the porphyry copper mineral exploration in the eastern Tibet, since the elevation of the region is very high and unaccessable by the conventional methods. In addition, there is a big potential for the copper exploration and several huge porphyry copper deposits have been, so far, discovered there. It is shown from the conventional geologic data that the mineralization of the study area is clearly controlled by the volcanic formation in the Tertiary and related closely to the immediate- felsic porphyry introsives in the Himalaya Movement. However, the results of the interpretation and analysis for the Landsat image revealed that the major mineral deposits are located in circle structures that are almostly the calderas developed in the Later Tertiary. Meanwhile, digital image processing with the Log-Residual, Mineral Indices and HSI Transformation algorithms have been also applied in this study in order to enhance and extract the alteration information related to the porphyry copper mineralization with the Landsat TM data and most of them are correspondence with the circle structures to be found from the visual interpretation of Landsat TM imge. Then, some target areas for the mineral exploration in the study area are delineated on the base of both the circle features and the alteration information to be mentioned above.