Recognition of geological structures in the Red Sea Basin based on potential field data and 2D seismic profiles: insights from Block 13, Sudan

The Sudanese Red Sea Basin is situated in a passive margin formed by a rift-drift transition between continental and oceanic systems. In this study, the gravity and magnetic data have been used to constrain the tectonic elements, major lineation trends, and the distribution of salt basins. 2D reflection seismic profiles were used to examine the tectonic boundaries, fault types, and salt structures of Block 13. The gravity anomalies showed two major north–south trending orientations of positive and negative residual gravity anomalies. Positive residual anomalies were interpreted to represent higher-density shale and carbonate deposits, whereas negative residuals were interpreted to mean salt deposits and sandstone. The magnetic map showed the anomalous total magnetic field, and the connected profiles allow identifying four significant zones with different magnetic patterns. The average trend of these zones can be classified into two groups: one trending northeast (45°) and the other trending northwest (315°). Although the salt deposits affect seismic data resolution, fault blocks and tectonic boundaries in the upper Wardan Formation (Upper Miocene phase) to lower Zeit Formation (Lower Pliocene) were interpreted using stratigraphic correlations. Growth and normal faults extend northeast to the southwest, with minor fault development identified in the Pliocene and Miocene strata in the southwestern part of the study area. At the same time, older normal faults cutting through the pre-Miocene salt succession were also detected. Also, the present work revealed salt structures such as salt domes and salt tongues.