Contribution of Remote Sensing to the Mapping of Lineaments and Ore-Mineral Occurrences in the Taghbalt Region, Moroccan Eastern Anti-Atlas

Abstract

The Taghbalet region is a part of the Paleozoic cover of the Moroccan Anti-Atlas, known by a rich mineral potential of vein type. This paper presents the results of a field investigation and processing of Landsat 8oli and Aster satellite images. The pre-processing allows for improving the image quality by applying a radiometric calibration, atmosphere correction and a pan-sharpening correction. Landsat-8 oli data is used to map structural lineaments including fracture and/or vein. C compositions ( RGB: 2, 5 and 7) and band ratios (5/7, 3/1, 4/3 and 5/7, 5/4, 3/1) were applied, both of which showed the lithological contrast between formations. Then directional filters (N-S, NE-SW, E-W and NW-SE) were applied on the spectral bands and principal component analysis to map the different lineaments. Validation and correction of lineaments obtained by automatic extraction are based on visual interpretation and field verification. The mining prospecting is performed using ASTER multispectral images. Therefore the results obtained show that we have two main directions; one E-W and the other NE-SW. The majority of these lineaments are concentrated in the south of the area. The results of mapping the hydrothermal alteration zones show us that these zones have a clear relationship with the fault.