Integrated remote sensing petrography and structural analysis for basement characterization in the Eastern Babouri-Figuil basin

Abstract

This study presents the first integrated characterization of the crystalline basement of the Eastern Babouri-Figuil basin in Northern Cameroon, combining Landsat 8 OLI/TIRS imagery processing with systematic field investigations, petrographic analysis, and polyphase structural mapping. Band ratios (B3/B6, B4/B5, B6/B7), principal component analysis (PC1, PC2, PC4), minimum noise fraction, and color composites enabled the discrimination of five lithological formations (F1–F5) comprising metamorphic rocks (orthogneiss, amphibolite, migmatite, amphibole schist), plutonic rocks (pyroxene-biotite granite, amphibole granite, aplite, pegmatite), and volcanic rocks (dolerite). The spectral signatures of these formations are consistent with field-identified mineralogical assemblages, confirming the reliability of the remote sensing approach. Structural analysis reveals three deformation phases: ductile phases D1 (ca. 600 Ma) and D2 (580–550 Ma) produced foliations (S1, S2), lineations (L2), boudinage (B2), and folds (P2) with preferential NE-SW orientation, reflecting Pan-African compression during Congo–West African craton collision. The brittle D3 phase (ca. 130–100 Ma) generated faults, fractures, and dykes associated with Cretaceous extensional reactivation linked to Atlantic Ocean opening. Lineament extraction using a 7 × 7 Sobel filter identified a dominant N-S trend with secondary NNE-SSW and E-W directions, in excellent agreement with 231 field fracture measurements, validating the satellite-based structural mapping. High-density fracture zones and magnetite occurrence in the northeastern sector indicate significant mineralization potential for Iron Oxide Copper–Gold deposits and rare metals. The integration of remote sensing, petrographic, and structural data produced a comprehensive litho-structural map, demonstrating the effectiveness of multi-method approaches for geological mapping and mineral exploration in regions with limited outcrop exposure.