ESTIMATION OF CURIE POINT DEPTH (CPD) ACROSS THE PAN AFRICAN BELT IN NORTHERN CAMEROON FROM AEROMAGNETIC DATA

The lithospheric thermal structure across the NeoProterozoic Pan African belt in northern Cameroon was estimated using a spectral analysis of magnetic data to determine the Cure Point Depth (CPD). The results show that there are two main regions which can be characterized by CPDs: 1) Shallow depths (~6.37 – 10.09 km) are located in several regions including the northern portions of the study area (toward the regions of Hina Marbak, Gawel and northern Moutouroua), the southeast (Kaele region), the south (Guider) and the southwest (Mayo Oulo), and 2) deeper depths (~10.68 –13.72 km) are located in the northeast (Mindif) and southwest (southern Moutouroua, Guider and Bossoum). Using these depths, a Curie isothermal point of 575°C, and a one dimensional heat flow model, a geothermal gradient was determined that ranges from 42.27 °C/km to 91.05 °C/km and heat-flow values ranging from 105.68 to 227.63 mW/m². The shallow depths of the magnetic sources correspond to high heat flow values and the correspondence of deep magnetic source depths with low heat flow values along the Bidzar-Mousgoy axis suggest that the approximately NW-trending extensional basins take up the strain caused by the NE to ENE trending strike–slip motions emanating from the Gulf of Guinea. These results are consistent with the existing post NeoProterozoic tectonic events affecting the study area.