IDENTIFICATION AND MAPPING OF MINERALS IN DRILL CORE USING HYPERSPECTRAL IMAGE-ANALYSIS OF INFRARED REFLECTANCE SPECTRA

A Portable Infrared Mineral Analyzer II (PIMA II) field spectrometer w as used to measure infrared reflectance spectra (1.3-2.5 mu m) of spli t drill core at 1 cm intervals in both the along-core and cross-core d irections. These data were formatted into an image cube similar to tha t acquired by an imaging spectrometer with 600 spectral channels, and multi-spectral and hyperspectral analysis techniques were used for ana lysis. Colour images and enhancements provided visual displays of the spectral information, while real-time digital extraction of individual spectra allowed identification of minerals. Absorption band-depth map ping and spectral classification were used to map the spatial distribu tion of specific minerals in the core. Linear spectral unmixing provid ed estimated mineral abundances. Analysis results demonstrate that mul ti-spectral and hyperspectral image analysis methods can be used to pr oduce detailed mineralogical maps of drill core. They suggest that the concepts and analytical techniques developed for analysis of hyperspe ctral image data can be applied to field and laboratory spectra in a v ariety of disciplines, and raise the question of the use of hyperspect ral scanners in the laboratory.