Geometrical Characterisation of the Mamfe Basin, Cameroon, from the Earth, Gravitational Model (EGM 2008)

Anatole Eugene Djieto Lordon,Thierry Stephane Kuisseu,Christopher M Agyingi,Mbohlieu Yossa,Yves Shandini

doi:10.5539/esr.v7n1p94

Abstract

Gravimetric studies using the ETOPO1-corrected high resolution satellite-based EGM2008 gravity data was used to define the surface extent, depth to basement and shape of the Mamfe basin. The Bouguer anomaly map was produced in Surfer 11.0. The Fast Fourier Transformed data was analyzed by spectral analysis to remove the effect of the regional bodies in the study area. The residual anomaly map obtained was compared with the known geology of the study area, and this showed that the gravity highs correspond to the metamorphic and igneous rocks while the gravity lows match with Cretaceous sediments. Three profiles were drawn on the residual anomaly map along which 2D models of the Mamfe basin were drawn. The modeling was completed in Grav2dc v2.06 software which uses the Talwini’s algorithm and the resulting models gave the depth to basement and the shape of the basement along the profiles. After processing and interpretation, it was deduced that the Mamfe basin has an average length and width of 77.6 km and 29.2 km respectively, an average depth to basement of 5 km and an overall U-shape basement. These dimensions (especially the depth) theoretically create the depth and temperature conditions for petroleum generation.

Highlights

In the quest for oil and gas, the subsurface of most of Cameroon’s basins have been thoroughly studied through the processing and interpretation of the gravity data (Fairhead et al, 1991; Kamguia et al, 2005; Ndougsa-Mbarga et al, 2007; Eyike et al, 2010; Oyoa et al, 2012; Mouzong et al, 2014)
The Mamfe basin in the Manyu Division of Cameroon according to geology, organic geochemistry and indigenous reports, could be a good petroleum prospect and as such is of high economic and scientific interest
The quality of the ground gravity data available to guide a detailed gravimetric exploration of the basin is poor in terms of spatial coverage and as such by using the high resolution satellite-based Earth Gravitational Model 2008 (EGM2008) gravity data this problem has been resolved to a great extent

Summary

Introduction

In the quest for oil and gas, the subsurface of most of Cameroon’s basins have been thoroughly studied through the processing and interpretation of the gravity data (Fairhead et al, 1991; Kamguia et al, 2005; Ndougsa-Mbarga et al, 2007; Eyike et al, 2010; Oyoa et al, 2012; Mouzong et al, 2014). This work is aimed at making some contribution to understanding the nature of the geometric framework of the Mamfe basin through the processing and interpretation of gravity data. Abate Essi et al, 2017 used satellite derived geavity data to study the subsurface of Central Northern Cameroon with structural and mining implications, it was used in this research to determine the geometrical characteristics of the Mamfe basin. We use the high resolution satellite-based Earth Gravitational Model 2008 (EGM2008) which has been corrected using the ETOPO1 to propose reliable values of the length, width and depth of the Mamfe basin and to give the shape of its basement

Objectives

Results

Discussion

Conclusion