Investigation of the Azraq sedimentary basin, Jordan using integrated geoelectrical and electromagnetic techniques

The Eastern Mediterranean has been used as a passageway for human migration from Africa to the Middle East, the Balkans and Europe. The Azraq basin in the eastern desert of Jordan has been a major spot for human settlements since the middle Pleistocene. The former lake in the basin centre has developed to a hyper-saline alluvial mudflat, the Qa' Al Azraq. In the mudflat thick sequences of alluvial sediments are deposited. Such sediment successions are promising archives used for reconstructing a paleoclimate. In order to identify geological structures and to derive suitable borehole locations in the area for a paleoclimatical reconstruction, the Transient Electromagnetic (TEM) and the Electrical Resistivity Tomography (ERT) methods were utilized. Two transects were investigated from the edge of the basin to the basin centre, crossing three geological formations. The data sets of both methods are interpreted by 1D and 2D inversion algorithms and appraised by inversion statistics. Previously uncertain geological boundaries are determined from geoelectrical models along both transects. Furthermore, a transition zone from fresh to saline groundwater is clearly detected.