Estimation of Curie point depth in southwestern Yemen from spectral analysis of aeromagnetic data

Abstract

Curie point depths in southwestern Yemen were determined from radially averaged power spectra of the reduced to the pole aeromagnetic data by the modified centroid method. The results show that shallow CPD zones occurred in the western and southeastern parts of the area associated mainly with Tertiary and Quaternary volcanic regions, respectively. The distribution of hot springs and hot groundwater wells through the area is correlated well with the mapped shallow zones and thermal gradient regions around them. On the other hand, the deepest CPD zone is attributed to a hot mantle upwelling underplating the crust beneath the volcanic plateau and crystalline basement margins in the middle part of the area. This spot forming the most probable source of magma for the Quaternary volcanic activity in the area. The observed geothermal activity at Al Lisi–Isbil, Damt, and Al Qafr fields is ascribed to the heat derived from shallow magmatic bodies, with temperature less than Curie temperature of magnetite, and also to the heat transferred from the underlain hot mantle spot through a net of deep faults affected this region.