Interpretation of Gravity Anomaly in the Area of Matomb (Center Cameroon) using Direct, Indirect and Inverse Methods

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Research areas:
Year:
2018
Type of Publication:
Article
Keywords:
Gravity Anomalies, Spectral Analysis, Ideal Body, Modeling
Authors:
F. Koumetio; C. T. Noutchogwe; R. Nouayou; E. Ndikum; V. J. T. Wandji; A. Dika
Journal:
IJRIES
Volume:
5
Number:
4
Pages:
106-111
Month:
July
ISSN:
2394-1375
BibTex:
Abstract:
The gravity maps display, in Matomb area, local oval culminations of high anomalies indicative of a presence of intrusive dense material in a subsurface that has not been characterized through a local study. The analyses of established gravity anomaly maps; the quantitative interpretation of residual anomalies by spectral analysis, by the inverse method and by 2.5D modeling allow for the characterization of the intrusive dense material situated at Matomb. The 2.5D model of the structure obtained shows six blocks of the same intrusive material having a density contrast of 0.27 g/ cm3 in comparison to the surrounding rocks which form a very homogeneous metamorphic assembly consisting mainly of gneisses and schists. This value of the density contrast is equal to that obtained using the inverse method. The different blocks are almost parallelepipedal lying all in the NNW-SSE direction. One of the blocks has its roof at the depth of about 1 km and its base at the depth of about 3 km while the other five have theirs at the depths of about 3 or 8 km. These values of depth are in agreement with the results of spectral analysis that located the interfaces at average depths of 0.9 km, 3.2 km and 7.5 km. Analyses show that our study area was affected by tectonic faulting in the NNW-SSE direction followed by an extensional tectonic in the WNW-ESE direction. The localization of deformation belts between the different blocks of the intrusive material of Matomb can also be a guide for mineral prospection