Lithological mapping of ophiolite complex with emphasis on chromite and magnesite exploration using remote sensing techniques

Abstract

This research employed the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) and Landsat Thematic Mapper (TM) data for lithological mapping and delineating of high potential chromite zone mineralization in ophiolite complexes. Abdasht, Soghan and Sikhoran chromite mining areas located in Sanandaj-Sirjan technically a part of the Esphandagheh ophiolite complex zone in Kerman province, southeastern of Iran have been selected for this research. In order to discriminate and to demarcate of the high potential chromite and magnesite rock zone, ASTER and Landsat TM bands properties have been utilized for running principal components analysis (PCA), band ratio (BR), minimum noise fraction (MNF), de-correlation stretch, log residual, spectral mapping methods and feature level fusion. A comparison between the image processing results with field investigation and primary geological map confirmed the concentration of chromite and magnesite mineralized zone associated with serpentinized dunite and hurzburgite. A new geological map showing high potential chromite zones and the boundary of lithological units was produced based on the interpretation of remote sensing data. The map can be used for geological exploration and mine engineering purposes. The data and methods used have emphasized high ability of the ASTER data to provide geological information for detecting chromite host rock such as serpentinized dunites and hurzburgite as well as lithological mapping at both district and regional scales. Additionally, Landsat TM data have also produced suitable results for lithological purposes on a regional scale. The approach used in this study is broadly applicable for exploring new chromite prospects and lithological mapping of the ophiolitic complexes especially in the arid and semi-arid regions of the earth.