Remote detection of vegetation stress for mineral exploration

Remote detection of geochemically-enriched and/or mineralized zones is invariably obstructed by tropical vegetation. Plants, however, take up from the substrate nutrients that influence their spectral characteristics. In this study, Landsat TM data are used to study the spectral characteristics of vegetation in stream sediment sample catchment basins and in mineralized zones in Catanduanes, Philippines. Vegetated areas are extracted from a classified image of the TM data. NDVI is also calculated. The mean NDVI and mean spectral band pixel values of vegetation are determined for the stream sediment sample catchment basins and the 30-m interval buffer zones around mineralized zones. Correlation analysis is performed on the geochemical and spectral data. Plots of mean NDVI and mean pixels values of vegetation versus element concentration levels and distance from mineralized zones are constructed. The results of analyses show that vegetation in and around geochemically-enriched and mineralized zones is stressed. A method to detect vegetation-covered mineralized zones is demonstrated