Estimation of Curie Point Depth (CPD) across the Pan African Belt in Northern Cameroon from Aeromagnetic Data

Abstract

The depth to the Curie isothermal point (CPD) was estimated using aeromagnetic data from northern Cameroon. The CPD was estimated using a two-dimensional power density spectral analysis of nineteen 30 × 30 km blocks over a series of Neoproterozoic lithologies associated with the Pan African orogeny. The results show that there are two main regions characterized by the CPD analysis: 1) Shallow depths (~6.37-10.09 km) which 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). The shallow depths can be related to two tectonic regimes: 1) the West-Central African Rift System with northeast-trending strike-slip faults emanating from the Gulf of Guinea and 2) the Cameroon Volcanic Line. However, the ultimate source of these shallow regions is interpreted to be related to the Cameroon Volcanic Line based on low seismic velocities imaged by recent broadband seismic studies which are concentrated along the northeast-trending strike-slip faults. An additional finding using the CPD depths, a Curie isothermal temperature of 580˚C and a one-dimensional heat flow model, was heat-flow values ranging from 105.68 to 227.63 mW/m 2 , which are above average global heat flow values and are therefore indicative of potential geothermal resources.

Assessment of the subsurface architecture insights across the Pan African Belt in Northern Cameroon: Applications of 2.75D Geophysical Modelling of Aeromagnetic Data from the Guider-Kaele Area.

“…The extent of these lowamplitude magnetic maxima implies that the magnetic susceptibility of the gneisses is relatively low, with some regions (small wavelength maxima within the region of anomaly 1) having higher susceptibility values. This could be due to high-grade gneisses or isolated ma c or metaigneous bodies (Ngoh et al, 2020). In fact, in the study area, the level of weathering of rocks is highly variable.…”

heat flow losing via earth's surface around of Khulj hot spring

“…5 could be approached in the form where B -is a constant and equals with Eq. 6 is used to estimate z t -the depth to the top of a magnetic layer in many articles (Bansal, et al, 2013;Nafiz, 2010;Xu et al, 2017;Ngoh et al, 2020;Wen et al, 2019;Arnaiz-Rodríguez and Orihuela, 2013;Quintero et al, 2019;Audet and Gosselin, 2019).…”