Structural Analysis Using Aeromagnetic Data: Case Study of Parts of Southern Bida Basin, Nigeria and the Surrounding Basement Rocks

Abstract

Structural analysis using aeromagnetic data over parts of southern Bida (Nupe) basin, Nigeria and the surrounding basement rocks was carried out to highlight linear structures and infer the effects of such features on the tectonic events in the survey area. The basin consists of the basal Lokoja Formation, overlain by the Patti Formation and capped by the Agbaja Formation. The basal Lokoja Formation is a sequence of matrix supported conglomerates and sandstones overlying the Pre-Cambrian to lower Palaeozoic basement. Magnetic rocks (iron ore) occur at the central, north eastern and south southern sections of the study area. Trend characteristics of magnetic lineaments were highlighted using the Euler deconvolution method. Werner and Euler deconvolution of aeromagnetic data profiles were utilized to determine the depth to magnetic sources. Depth to magnetic sources along aeromagnetic data profiles ranges from 0.01 km to 0.51 km with an average value of 0.128 km. Deductions made from the research are; mineralization is structurally controlled in parts of the survey area with kaolin occurring along a lineament around Share, western part of the survey area. The occurrence of subsurface linear structures may be due to discontinuities caused by faulting of country rock. Lineaments' trends inferred include the east-west, north-south, northeast-southwest, north northeast-south southwest and northwest-southeast directions, with the north northeast-south southwest trend being dominant. Werner deconvolution plots for profiles ZZ and HH located at the central and southern sections of the survey area respectively; are inferred to be basement rock fractures beneath the sedimentary rock.

Investigation of Hydrogeological Structures of Paiko Region, North-Central Nigeria Using Integrated Geophysical and Remote Sensing Techniques

“…Present are the minor N-S fractures which are attributed to brittle deformation and the twin conjugate sets of NE-SW and NW-SE trends, produced by transcurrent movements [38]. The age relationships of the conjugate fracture sets cannot be easily resolved from their relative dispositions on the map, but it has been established that NW-SE trending lineaments are analogous to the predominant trend of the Bida Basin [35]. The structural framework of the Nigerian Basement Complex is dominated by the NE-SW lineaments [35,36].…”

“…This deformation event is closely related to the formation of the schist belts and mylonites in the region. [35] have attributed NE-SW trend to the landward extension of the Chain and Romanche Fracture Zones from the Atlantic Ocean [36].…”

Magnetic Basement Depth and Structure over Parts of Bida Basin, Nigeria Interpreted from 2-D Spectral Analysis and 3-D Euler Deconvolution

“…The method is therefore well established in its use in inferring depth to magnetic sources (Bhattacharya, 1966;Spector and Grant, 1970). Previous studies on the analysis of aeromagnetic data have been carried out in Bida Basin by Bemsen et al (2013), Obi et al(2015), Megwara and Udensi (2014), and Nwankwo et…”

“…al. (2008).Similarly, Megwara and Udensi (2014) carried out a structural analysis of the aeromagnetic data over the study area using the Werner and Euler deconvolution. The analyses which was carried out along profiles revealed depths to the magnetic sources of the range 0.01 km to 0.51 km with an average value of 0.128 km.…”

Spectral depth analysis of some segments of the Bida Basin, Nigeria, using aeromagnetic data

“…For instance, Ofor et al (2014) carried out a study of Pategi and Egbako areas of the lower Bida basin and revealed two prominent layers; with average values of 0.59km and 3.1km respectively. Megwara, and Udensi (2014) also carried out structural analysis using aeromagnetic data over parts of southern Bida basin and the surrounding basement rocks and found the depth to be within the range of 0.01km to 0.51km with an average value of 0.128km. Ojo and Ajakaiye (1989) delineated the presence of a positive gravity residual centre in the basin.…”