Abstract Crustal evaluation of the northern Red Sea rift and Gulf of Suez, Egypt from geoph.pdf

/locate/jafrearsci Journal of African Earth Sciences 45 (2006) 257–278Crustal evaluation of the northern Red Sea rift and Gulf of Suez, Egypt from geophysical data: 3-dimensional modeling Salah Saleh a,b, Thomas Jahr b, Gerhard Jentzsch b,*, Ahmed Saleh a, N.M. Abou Ashour c a National Research Institute of Astronomy and Geophysics, 11421 Helwan, Cairo, Egypt b Institut fu?r Geowissenschaften, Friedrich-Schiller-Universita?t, Burgweg 11, D-07749 Jena, Germany c Ain Shams University, Faculty of Science, Geophysical Department, Cairo, Egypt Received 8 December 2003; received in revised form 31 May 2005; accepted 6 February 2006 Available online 29 March 2006Abstract Combined 3-D interpretations of gravity and aeromagnetic data have been used in addition to continental and marine seismic profiles, well logs and geological cross-sections. The combination of gravity and magnetic data has improved the geometry and the density dis- tribution in the 3-D calculated profiles. Results of the current work reveal possible crustal thickness and density distribution between the sedimentary cover and the upper mantle including the Moho discontinuity. The Moho depth map of the region, as obtained from the 3-D modeling exhibits various crustal thickness distributions. The type of crust changes gradually from continental to oceanic, from north to south. The zone of crustal thinning coincides mostly with zones of low-density, heated anomalous upper mantle beneath the rift floor (7 km). The eastern plateaus (the Red Sea hills) show by far the largest crustal thickness in the region (32 km). The Moho relief, as indicated from magnetic interpretation, shows a poor flattening especially in the eastern region. This is contrary to what is given by other authors. However, the present results are in good agreement with the geothermal gradient values in the Red Sea. The interpretation of magnetic data of the Red Sea Rift shows that the spreading rate of the part south of latitude 26.5 N agrees