Gravity-based structural and tectonic characterization of the Shendi-Atbara Basin, Central Sudan

Abstract

This study employs gravity data analysis techniques to investigate the subsurface structural framework and lithological variations of the Shendi-Atbara Basin in Sudan. This basin is influenced by both the Mesozoic rifting associated with the West and Central African Rift System (WCARS) and the Neoproterozoic tectonics of the Nubian Shield. High-resolution satellite gravity data were analyzed using potential field methods including anomaly separation, edge detection, and 2D and 3D modeling to delineate primary structural features and density interfaces. Various edge detection techniques were applied to identify lineament structures, and the results were integrated to construct a comprehensive structural map of the region. This map was subsequently analyzed to interpret the tectonic evolution and subsurface geology. Structural analysis revealed three dominant fracture sets: NW-SE extensional fractures, NE-SW release fractures, and N-S shear fractures. Gravity modeling indicated that the thickness of the sedimentary sequences in the Shendi-Atbara Basin reaches up to 4800 m. A notable high-density anomaly southeast of Shendi is interpreted as an intermediate to mafic igneous intrusion, corroborated by surrounding structural patterns identified through edge detection and modeling. These findings provide valuable insights into the basin's tectonic evolution. The identified fractures serve as important guides for groundwater and mineral resource exploration, particularly given the presence of high-density sources and iron-rich sedimentary formations in the region.