Interpretation of aeromagnetic data in terms of surface and subsurface geologic structures, southwestern Yemen

The studied area is located in the southwestern part of Yemen between latitudes 13 degrees 00' N-14 degrees 00' N and longitudes 43 degrees 30' E-45 degrees 00' E. The used data include the geological and aeromagnetic maps of the area (sheet 13G scale 1: 250,000). The present work aimed to understand the subsurface regional structures and their contributions to the surface geologic structures through the interpretation of the available aeromagnetic data. The aeromagnetic map was subjected to critical interpretation using several analysis techniques, including spectral analysis, regional/residual separation, analytical signal, and Euler deconvolution. The results indicate that the area is affected mainly by four tectonic events through its geologic history. Among these events, the Late Precambrian tectonic activity (Najd fault system, trending NW-SE) plays an important role in defining the tectonic framework of the area, whereas the more recent tectonic event (during the Cenozoic) is associated with the emplacement of trap volcanic series and the opening of the Gulf of Aden and the Red Sea. The depth of the magnetic anomaly sources was computed using spectral analysis and 3D and 2D Euler deconvolution techniques and found to lie between less than 500 and 7,660 m.