Spectral analysis and gravity modelling in the Yagoua, Cameroon, sedimentary basin

Abstract

A gravity survey is carried out in the far north of Cameroon, covering an area of about 15 000 km² in the Yagoua sedimentary basin, located between longitudes 14°20' to 15°50'E, and latitudes 9°45' to 11°N. Using a density of 2.7 g/cm³ for the crust and removing a second–degree trend surface for modelling, we determined the residual anomalies. Further investigations provide depth of gravity sources, basement structural trend, nature of intrusive bodies and thickness of sediments in the basin. A negative anomaly of about –18 mGal near Moulvouday suggests a thickness of sediments of 3.1 km extending north east. A 2.5D modelling has been carried out along two profiles P₁ and P₂. The depths estimated from spectral analysis and 2.5D modelling are coherent. The combination of the spectral analysis and 2.5 D modelling has led to the demarcation of the Yagoua basin.