Aster Mapping of Limestone Deposits and Associated Lithounits of Parts of Chikkanayakanahalli, Southern Part of Chitradurga Schist Belt, Dharwar Craton, India

Economically viable limestone deposits are mostly formed by calcite minerals, and these minerals are widely used in manufacturing of cement, mortar, fertilizer and flux for smelting of iron ores, and mapping of such deposits is significant and important in scientific research. This study examines the capability of Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) with the wavelength range visible–near-infrared and short-wave infrared spectral bands to map such limestone carbonate deposits and associated lithounits occurred in and around of Chikkanayakanahalli, southern part of the Chitradurga schist belt using minimum noise fraction (MNF) and decorrelation stretching methods. The study results that (1) the RGB image of MNF (R: B1; G: B2; B: B3) of ASTER is capable of discriminating the limestones and associated different rock types, namely banded magnetite quartzites (BMQ), graywackes, Mn- and Fe-rich cherts, metabasalts, granitic gneisses, granitoids and migmatites and (2) the decorrelation stretch image of ASTER bands 8, 3, 1 of the ASTER delineated clearly the limestones and associated rocks of the study area. Study of spectral signatures of field samples of such economic limestones in the wavelength of 350–2500 nm using Fieldspec3 Spectroradiometer showed the spectral absorption near 2.32 μm due to the presence of calcite minerals in the rocks. The results of study are cross-verified in the study area and confirmed through petrological and chemical analyses of the samples. This study bespeaks the potential of ASTER sensor and application of image processing methods to map the economic limestone deposits and associated rocks of the study area.