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The new high
resolution aeromagnetic data of parts of the Middle Benue
Trough Nigeria have been qualitatively interpreted to assess
some of it features. The regional-residual separation was
performed with a first order polynomial using prolific
program. The residual data obtained was contoured into 2-D
and 3-D maps and this revealed two prominent magnetic
anomaly source intensities; the low frequency anomaly and
the high frequency anomaly sources. The low frequency
anomalies emanates from deep seated bodies in areas with
thicker sediments and may be viewed as the magnetic basement
depth. The high frequency anomaly emanates from shallow
seated geologic bodies in areas of shallower sediments and
may be attributed to the volcanic rocks that intruded into
the sedimentary formation and this could possibly be
responsible for the mineralization found in the area.
Varying magnetic highs and lows have been found in the study
area which might likely indicate undulating basement surface
and likely traps. The general trend in the orientation of
the magnetic contours and lineament was found to be
predominantly in the NE-SW direction, an attribute of the
Pan – African Orogeny trends. The regional field was found
to dip gently and uniformly towards the North-eastern part
of the study area from the South-western part with a
regional gradient of 205gammas/km. Prominent closures and
undulations are more in the basement surface around Gboko
area than the Makurdi area. It’s very likely that this study
area with the oldest marine sedimentary layer of the Albian
Age, Coniacian – Turonian Age, and Turonian – Senonianage
possessing these favourable geologic features and traps may
have the potential to generate hydrocarbon if other
conditions are met.
Keywords: Middle Benue Trough, Magnetic anomaly, high
resolution aeromagnetic data (HRAM), magnetic basement
depth, magnetic highs and lows, high frequency and low
frequency anomaly source.
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