A STRUCTURAL ANALYSIS OF THE BENUE TROUGH, NIGERIA FROM GEOPHYSICAL DATA
A STRUCTURAL ANALYSIS OF THE BENUE TROUGH, NIGERIA FROM GEOPHYSICAL DATA
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Date
1982-11
Authors
ASHIEKAA, AKAAYAR JOHN
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Abstract
The main aim of this study was to produce an
aeromagnetic map of the Benue trough in order to resolve
some of the peculiarities of the trough namely, its
origin, evolution its lateral spreading.
Gravity and magnetic data were acquired for this
study and interpreted.
From the interpretations and results of the aeromagnetic
data, the Benue trough is characterised by areas of
magnetic lows through its entire length especially along
its flanks. The amplitudes of these anomalies vary from
-60 to -300 gammas and the depths to the top and bottom
for causative bodies vary from 200 to 3000 m and 3500 to
14000 m respectively.
The magnetic lows along the flanks mark the probable
structural boundary between the trough and the other
complexes.
The central anomaly has been attributed to a fracture
zone within the trough which provides a possible
explanation to its abnormal width. This has been further
interpreted to indicate the possibility of two rifts
within the trough.
The study indicates the absence of oceanic crust
beneath the trough, thus no seafloor spreading unlike the
Red Sea,
The interpretation of the Shendam to Takum gravity
profile confirms the magnetic interpretation. Gravity
lows are observed at the edges of the trough; and
that the trough consists of two synclines separated
by the Wukari anticline.
Finally, the study has revealed that the Benue
trough is a tensional continental rift valley filled
with Cretaceous sediments.
Description
A Thesis Submitted in partial fulfillment of the requirements
for the degree of Master of Science, Applied
Geophysics
Department of Physics
Ahmadu Bello University
Zaria.
NOVEMBER, 1982
Keywords
STRUCTURAL,, ANALYSIS,, BENUE,, TROUGH,, NIGERIA, GEOPHYSICAL,, DATA.