STRUCTURAL ANALYSIS OF HIGH-RESOLUTION AEROMAGNETIC DATA TO MAP OUT LITHOLOGICAL STRUCTURES OVER NORTHCENTRAL NIGERIA

ABSTRACT This study focuses on structural mapping using improved edge detection filters applied to high-resolution aeromagnetic data from selected parts of the Middle Benue Trough, North-central Nigeria. Aeromagnetic surveys, a cost-effective and efficient geophysical method, provide critical insights into geomagnetic variations caused by differences in the magnetite content of rock units. The research aims to generate Total Magnetic Intensity (TMI) anomaly maps, estimate the depth of the causative anomalous bodies, and enhance interpretations through advanced processing techniques such as Reduction to the Magnetic Equator (RTE), Tilt Angle Derivatives, and Analytical Signal (AS). The data for this research was sourced from the Nigerian Geological Survey Agency (NGSA) and processed using Oasis Montaj software. Key enhancements, such as RTE and Tilt Angle Derivatives, were applied to delineate subsurface structures and variations in lithology. Results revealed significant geomagnetic variations, with high-amplitude magnetic anomaly values predominantly observed in the western regions, correlating with sedimentary rock intrusions. Low-amplitude magnetic intensity values toward the southern region suggest geological structures (fractures and faults) with low magnetic content. The study concludes that the area exhibits basement complex rocks and sedimentary formations, with high-intensity anomalies in NE-SW and NW-SE directions