An Estimation of Magnetic Contact Location and Depth of Magnetic Sources in Ilesha, Nigeria, Using Magnetic Gradient Techniques
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Date
2015
Authors
Ozebo, V.C.
Ogunkoya, C.O.
Makinde, V.
Omeike, M.O.
Journal Title
Journal ISSN
Volume Title
Publisher
African Review of Physics, ICTP, Italy
Abstract
Mapping the subsurface structures in the study area can shed some light on the structural location of mineral deposits, its relation to tectonic instability and the depth of magnetic bodies. This study presents an interpretation of aeromagnetic data at Ilesha, located in Osun State of southwestern Nigeria, to map the subsurface locations of the area
The structural interpretation of magnetic data was achieved by applying Horizontal Gradient Method (HGM) and Analytical Signal Method (ASM), an advanced interpretation technique that provides contact locations and depths of magnetic sources. Results of these two methods reveal a two-source depth model. The depth of the deeper magnetic source bodies ranges from 1.46km to 2.55km with an average of 2.01km for ASM, and 2.92km to 5.48km with an average of 4.20km for HGM. These magnetic source bodies were identified with the magnetic basement. The shallower magnetic sources ranging in depth from 0.348km to 1.28km with an average depth of 0.814km for ASM, and 0.478km to 2.50km for HGM could be attributed to near-surface magnetic rocks that intrude into the sedimentary formation