Geological mapping from satellite imagery and lineament detection in the Imilchil-Aghbala region (High Atlas central and Middle Atlas ridges zone, Morocco)

The Imilchil-Aghbala region is located in the provinces of Tinghir and Khenifra in Morocco and is part of the High Atlas central and Middle Atlas ridges zone. The region is characterized by a structured Jurassic sedimentary series. The purpose of this study is to conduct geological mapping and extract lineaments. Geological mapping by using satellite imagery is a valuable tool in geology to understand the surface, as well as, the geology of subsurface for given area. The acquired images need to be processed to enhance the geological features, and then analyzed to identify and extract geological features such as lithological units, faults, and fractures. This can be achieved through various techniques such as spectral analysis and directional filtering techniques, which were applied to extract the lineaments. Geostatistical analysis of the Meso-Cenozoic terrain fracturing in the region was conducted using Landsat 7 ETM+ satellite image analysis. Principal component analysis (PCA) and directional filtering techniques were applied to extract the lineaments. The results showed that the processing and analysis allowed for successful lineament extraction and the creation of an accurate geological map of the rock cover. The junction between the High and the Middle Atlas complex system provides an essential link between seismic activity and geological lineaments The lineaments were observed and have the main directions of northeast (NE)-southwest (SW) to east northeast (ENE)-west southwest (WSW), with minor directions corresponding to fracture regimes. The fractures were organized into high-density networks or corridors, followed by mountain ranges, major faults, and hydrological networks. The results obtained are compared with existing geologic maps, as well as with the previous studies, and it is validated through a field mission in the region studied to be a useful tool for update the existing maps.