2-DIMENTIONAL MODELS OF THE STRUCTURAL FEATURES WITHIN THE LOWER BENUE AND UPPER ANAMBRA BASINS NIGERIA, USING (2009) AEROMAGNETIC DATA

Abstract

Analysis base on the CET shows that the basement rocks to the North and southern edge of the study area intrude into the sedimentary formation. At the lower (middle-portion) of the study area (within Angba and otukpo sheets) are structures that are Basaltic rocks that intrude into the basement. It is believed that these structures must have predated the depositional period of the sedimentary formation. Several fracture and fault lines are detected on the CET map, most prominent among is that which start from the eastern end (latitude 7.45o and longitude 8.30o) and ends at the southern end (Latitude 7.00o Longitude 7.45o). Cutting the south western corner of the study area diagonally. Secondly is that which runs vertically and is parallel to the course of River Niger within this area, supporting the assertion that the River Niger is structurally controlled. The 2-dimensional models of the six profiles revealed sedimentary formations whose susceptibility values are zero (0). Maximum depth of about ten (10) kilometers was obtained within the southern end of the study area, but a maximum thickness of sedimentation of about four (4) kilometers was observed on profile six within Nkporo formation. The basement susceptibility varies from 0.002 to 0.004 but in some places it is as high as 0.007.