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Interpretation of Aeromagnetic Data of Kam, Using Semi-Automated Techniques

Author Affiliations

  • 1Department of Pure and Applied Physics, Ladoke Akintola University of Technology, Ogbomoso, NIGERIA
  • 2 Department of Physical Sciences, Ondo State University of Science and Technology, Okitipupa, NIGERIA

Int. Res. J. Earth Sci., Volume 2, Issue (2), Pages 1-18, March,25 (2014)

Abstract

The Benue basin is a major geological formation underlying a large part of Nigeria, and also a part of the broader Central African rift system. The Upper Benue basin being part of Benue basin is believed to be rift valley and is expected to be a major depositional basin, because rifting structures are often good sites for mineralization. The strategic economic importance and the availability of data from the study area arose the interest of many researchers including this present work to focus their attention on the area in search of geological features that are favourable to mineral deposition in the basin. In this work, the interpretation of the data extracted from the aeromagnetic map of Kam, an area in the upper Benue basin which covers from latitude 08°00' to 08°30' N and longitude 11°00' to 11°30' E was carried out using a semi- automated techniques involving the analytic signal technique to delineate linear geologic structures such as faults, contacts, joints and fractures within the study area in a bid to unravel the gross subsurface geology of the area which would in no doubt help in better understanding and characterization of the area investigated. The residual magnetic field data was subjected to a filtering technique, the analytic signal which was employed to study source parameters which include location, depth and susceptibility contrast of the identified magnetic anomalies in the basement rocks. The results obtained from both profiling curves and depth contour map showed that the study area is magnetically heterogeneous and the basement is segmented by faults. Based on the results obtained from both profiling curves and depth contour map, it was revealed that the study area is divided into three basinal structures; deep sources ranging between 5km and 8.5km and the area is recommended for further investigation especially for its geothermal energy potentials. The intermediate depths between 2km to 4.5km correspond generally to the top of intrusive masses occurring within the basement, a depth deep enough for possible hydrocarbon deposit. Shallow depths between 0.01km and 2.5km are attributed to shallow intrusive bodies or near-surface basement rocks probably isolated bodies of ironstones formation concealed within the sedimentary pile.

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