Assessment of depth to magnetic sources and 2D magnetic modelling using high resolution aeromagnetic data in parts of Nupe Basin, North Central Nigeria

Abstract

High resolution aeromagnetic data of parts of Nupe Basin, North Central, Nigeria 
comprising of sheets 162 (Akerre) 163 (Zungeru), 183 (Egbako), and 184 (Bida) were used to 
evaluate the depth to magnetic source and generate 2D magnetic modelling of the study area. 
The data was analysed using Oasis motaj software, by applying depth estimation method such as 
Euler Deconvolution (ED), Source Parameter Imaging (SPI), and 2D forward and inverse 
modelling.   
Results obtained from the Euler Deconvolution and SPI show that the estimated depth to 
magnetic sources ranges from 0.38 km to 1.44 km and 0.63 km to 1.48 km respectively. The 
depth computation indicates the presence of shallow sources in the northern, eastern, and north
eastern parts of the study area, and deep sources in the north-western, western, and southern parts 
of the map. The 2D magnetic modelling revealed magnetic intensity along the profile ranging 
from –100 nT to 60 nT, and depths along the profile vary between 0.5 km and 3.0 km. Structural 
features which were revealed to be fault can be seen across the profile. The study revealed that 
the relatively shallow depths suggest the presence of near-surface magnetic sources, and also 
establish that the overburden thickness, which may be attributed to shallow granitic intrusions 
lies in the regions where short wavelength anomalies can be observed. Generally, it was 
observed that the southern, western, and north-western part of the study area is characterized by 
thick sedimentation 
Keyword: Aeromagnetic data, magnetic modeling, depth to magnetic sources.