Ultramafic rocks discrimination from country rocks, using Landsat 7 ETM+ image data processing, in the Sierra Chica, Córdoba

Abstract

Techniques and strategies were developed in image analysis and spectral characterization in a reasearch to identify and map the ultramafic rocks and to detect and outline these bodies at Sierra Chica of Córdoba. Field data and specific location of these bodies were used to check the results obtained from the digital treatment. Landsat- 7 ETM+ image data are employed in digital processing, including band combination, band rationing and spectral classification to reach the purpose of this work, in spite of vegetal cover and reduced exposed area of these rocks. Ultramafic rocks, part of the "Eastern Belt", intercalates with intermediate to high grade metamorphic rocks, located in the Sierras Pampeanas of Córdoba, between Sierra Grande and Sierra Chica. Maximum likelihood and box classifications are the best performance in digital image processing. This is consistent with other way to recognize these bodies.