Interpretatin of geopotential field anomalies in area Around Sohag, Egypt

Abstract

The investigated area Ues in the central part of Egypt (around Sohag). The present study aims at obtaining information about the subsurface geological conditions in the area from the analysis and interpretation of both gravity and magnetic data. The resuls obtained suggest a general northward increase in basement depth (2-3 km). The basement rocks were influenced by major tectonic trends having NE-SW.NW-SE and E-W directions. The course of the River Nile in the examined area is chracterized by small basement depth compared to the eastern and western parts . In general the course of the River Nile is chracterized by subsidence in certain parts , while uplift is observed in its eastern and western parts. Origin of the major gravity anomaly low (A), at the west- central part of the area, and that of magnetic low on the aero-magnetic map at the same location may point to basement structures (of granitic type) or may suggest an increase of the sedimentary section with varying subsurface sedimentary facies at the location. The depth to the causative bodies below the gravity anomalies (A&B), on the Bouguer gravity anomaly map, varies from 1.5 to 5km. Origin of these anomalies is possibly due presence of basement bodies (e.g granitic) of different types than the surroundings of basins filled with sediments of different facies than the surroundings. Drilling data are needed to confirm this suggestion.