Magnetic Characterisation of Rocks Underlying FUTA Campus, South-Western Nigeria

Abstract

The Federal University of Technology, Akure Campus is predominantly underlain by the Migmatite-gneiss-quartzite complex of the West African Basement Rocks, which forms part of the Pan-African mobile belt. Geo-magnetic characterisation of the underlying rocks was conducted in order to determine the rock boundaries and geologic features within the near surface and subsurface areas of the Campus. Both qualitative and quantitative interpretations of total magnetic intensity data obtained in the area yielded results in terms of different rock units, linear magnetic fabrics, subsurface features and depth to basement of the rocks. On the basis of magnetic response, four rocks units including Granite, Migmatite gneiss, Charnokite and Quartzite were delineated, with varying degree of fabrics’ alterations. Depth-to-bedrock in the Campus varies from 0 to 98.5 m, while depth to fracture/fault in the area falls between 0.1 m and 149.6 m.

Keywords: Geo-magnetic characterisation, depth-to-bedrock,   rock fabric, total magnetic intensity, magnetic response