IDENTIFICATION OF REGIONAL TECTONIC STRUCTURES OF CAMEROON VOLCANIC LINE USING GRAVIMAGNETIC AND 2D LAPLACIAN TERRAIN ANALYSIS TECHNIQUES

Abstract

Cameroon is made up of an extensive tectonic system that includes a geologically significant structure in Central Africa called the Cameroon Volcanic Line (CVL). In this study, a multi-phase approach was applied to identify new tectonic structures across the CVL using gravity data from the XGM2019e_2159 model, magnetic data from EMAG2, and topographic data from GMRT. First-order and second-order vertical derivatives of both magnetic and gravity data were used to filter geologic structures in the study areas. To understand the trend of the structures based on the potential field, edge enhancement of potential-field data using normalized statistics (standard deviation edge detection) and phase sym­metry were applied. Phase symmetry provides phase-based formulation that can detect ridges and valleys corresponding to geological structures regardless of anomaly strength, making it robust to noise and interpolation artifacts. For de­tailed analysis to delineate new and already existing lineaments, a 2D Laplacian terrain transformation of the topographic data was computed at various heights from 20 to 105 km. The gravitational and magnetic structures discovered were superimposed on the transformed topographic map and drawn out to identify the orientation and direction of the faults. The study further illustrates the occurrence of potential geologic features associated with gravity anomalies, magnetic anomalies, and the new lineaments identified in the area. These results highlight that the lineaments identified are mostly orientated SE-SW and act as evidence of the still continuing process of deformation of the CVL. This finding is essential for advanced regional tectonic modeling across the CVL.