SPECTRAL ANALYSIS AND INTERPRETATION OF AEROMAGNETIC ANOMALIES OVER THE UPPER BENUE TROUGH, NIGERIA
SPECTRAL ANALYSIS AND INTERPRETATION OF AEROMAGNETIC ANOMALIES OVER THE UPPER BENUE TROUGH, NIGERIA
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Date
1987-08
Authors
NWOGBO, NWOGBO
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Abstract
Aeromagnetic data of the Upper Benue Trough
have been analysed by one- and two-dimensional spectral
analysis to determine the lateral variation in
sedimentary thickness and structure under the basin.
A two-dimensional standard model interpretation of
an aeromagnetic profile was also presented as a
supplementary technique. The area investigated covers
the portion of the trough from 09° 00' - 12° 60'N
and 009° 30' - 012° 30'E.
Spectral depth determinations to magnetic sources
in the region give four depth ranges namely: 9.40km
to 31.52km, 4.37km to 5.10km, 2.0km to 2.83km, and
0.04km to 0.96km. Deep source depths occuring at
9.40km and 31.52km refer respectively to some layer of
intra-crustal source structures, and to the lithologic
interface corresponding to the crust-mantle boundary.
The intermediate mean depths varying between 4.37km
and 5.10km may represent the top of some intrusive
material occuring within the basement. Some of these
intrusions as indicated by the two-dimensional model
interpretation occur at depths of up to 6.0km. Mean
depth values in the range of 2.0km to 2.83km agree
with previous estimates from gravity data and may
relate to the magnetic level corresponding to the true
basement surface. This depth range indicate clearly
the magnitude of the undulation of the basement
topography in the study area. Variations in the depth
Description
A thesis submitted to the Postgraduate School,
Ahmadu Bello University, Zaria in partial
fulfilment of the requirements for the award
of the degree of Master of Science in
Applied Geophysics.
Keywords
SPECTRAL, ANALYSIS, INTERPRETATION, AEROMAGNETIC, ANOMALIES, OVER, UPPER, BENUE, TROUGH, NIGERIA