Enhancing geological and structural mapping and identifying mineralization potential in the Tibesti Region through advanced remote sensing techniques

Abstract

This study investigates the geological framework and mineralization potential of the Tibesti region in southern Libya using advanced remote sensing techniques, with emphasis on areas that remain inaccessible due to security constraints. Multispectral Landsat-9 OLI data were processed through a series of atmospheric, radiometric, and noise-reduction corrections to enhance spectral accuracy. Band ratios, False Color Composites (FCC), and Principal Component Analysis (PCA) were applied to identify key alteration minerals, particularly iron oxides and Al-OH–bearing clay minerals such as kaolinite, illite, and montmorillonite, which serve as indicators of hydrothermal alteration. Supervised classification using reflectance signatures derived from the geological map of northern Chad enabled the extension of geological mapping into poorly studied northern Tibesti, confirming continuity of major lithological units including Cambro-Ordovician and Devonian sandstones, granodiorite, and Nubian Sandstone.

Structural analysis incorporated hill shade models and enhanced band composites, allowing the delineation of major fault and fracture systems. Manually extracted lineaments were used to generate a fault-density map, revealing structurally intense zones closely associated with intrusive bodies. Integration of structural data with hydrothermal alteration mapping demonstrates significant overlap between high-density fault zones and clay alteration belts, identifying priority targets for mineral exploration. Correlation with known illegal gold-mining sites further validates the remote sensing results and highlights the region’s mineral potential.

Keywords: Remote sensing, geological mapping, Lineament analysis, Minerals exploration, Landsat-9, machine learning classification.