Structural Analysis Using Upwards Continuation / Lineaments Trends Analysis on Aeromagnetic Data: A Case Study of Southern Nigeria Basins

Abstract

Twenty aeromagnetic maps were used for this study, which covers parts of Southern Sedimentary basins and their adjourning basement flanks in Nigeria. The aeromagnetic maps were acquired from the Nigeria Geological Survey Agency on a scale of 1: 100,000. The data was digitized manually along flight lines and a total of 16,689 data points obtained. The information was processed using computer techniques such as map merging, reduction to pole, polynomial filtering, upwards continuation, manual trend analysis and depth estimates. The results from upwards continuation reveals five major deep-seated anomalous fracture trends which could characterize major depositional centers. Lineaments trend results indicate dominant NE –SW trends within the Niger Delta, Mamfe basin, Lower Benue Trough, and Anambra basins, while the Calabar Flank area has a NW –SE Lineaments trends. Manual depth estimates indicate grater sediments thickness within the deeply seated anomalies ranging between 2.5km -10.0km, and within the shallow anomalous structures depth to source of anomalies varies between 1.0km – 2.0 km .The identified five major deep-seated anomalies  characterize good prospecting sites for possible hydrocarbon deposits accumulation.