Crustal Structures Inferred from Combined Terrestrial and Earth Gravity Data beneath the Babouri-Figuil and Mayo Oulo-Lere Basins, North Cameroon and South Chad
DOI: https://doi.org/10.36956/eps.v3i1.928
Received: 18 August 2023; Received in revised form: 1 February 2024; Accepted: 27 February 2024; Published: 11 March 2024
Copyright © 2024 Bouba Saidou, Apollinaire Bouba, Valentin Oyoa, Kasi Njeudjang, Joseph Kamguia, Alidou Mohamadou. Published by Nan Yang Academy of Sciences Pte. Ltd.
This is an open access article under the Creative Commons Attribution-NonCommercial 4.0 International (CC BY-NC 4.0) License.
Abstract
In this work, the study of the crustal structure of the Babouri-Figuil and Mayo Oulo-Lere sedimentary basins was carried out through the interpretation of gravity data. These data were obtained by combining the terrestrial gravity data obtained from the Earth Gravitational Model 2008. The analysis of the terrestrial Bouguer anomaly maps reveals both negative and positive anomalies. Negative anomalies, i.e., low-density signatures, are interpreted as specific rock types on the basis of the geological knowledge of the region while the positive anomalies are attributed to basaltic rocks underlying a generally granitic environment. The empirical method was used to distinguish anomalies due to deep structures from those due to near-surface structures. This method testifies that the residual map of degree 4 is appropriate. Six profiles are drawn on this residual Bouguer anomaly map and are interpreted using spectral analysis and 2D modeling methods. The results indicate that the mean depths of mass sources at the near-surface of the Babouri-Figuil and Mayo Oulo-Lere sedimentary basins are located at 1.50 km and 1.55 km, respectively. Moreover, the Babouri-Figuil Basin is constituted of two formations while the Mayo Oulo-Lere Basin exhibits three distinct formations. These models also help clarify the geological structure of the study area as well as the thicknesses of the sedimentary basins.
Keywords: Earth Gravitational Model 2008, Bouguer anomaly, Empirical method, Spectral analysis, 2D modeling