The application of spectral characteristic space method to the alteration information extraction of lake superior-type iron deposit

The field study of overseas iron ore deposits is difficult because of its remote location. The spectral characteristic was used to extract alteration information in view of the limitation of the traditional methods in this paper, aiming to explore alteration information extraction from hyperspectral images for the Lake Superior type iron ore to facilitate overseas prospecting. A two-dimensional spectral characteristic space takes on an anisotropic feature in associated distribution of two principal bands after principal component analysis. The distribution is usually combined by oval clusters. The scatter points were enclosed in oval clusters of alteration information, and the mean spectra of abnormal scatter points were matched with mineral spectra from United States Geological Survey (USGS) spectral library by means of spectral feature fitting to ensure the type of alteration minerals. Spectral characteristic space method was described with the instance of Lake Superior-type iron deposit-Aguas Claras iron area in Brazil. Hematite, chlorite and other minerals were extracted in this study. It is found that the type and distribution of extracted altered minerals were consistent well with geological condition. ©, 2015, China University of Geosciences. All right reserved.