Abstract
Detailed aerial and ground radiometric surveys were conducted on the coastal plain of the Mediterranean Sea, on both sides of the Damietta estuary of the River Nile. Auger samples--representing the upper 1 meter--were also collected and analyzed for the two principle radioactive minerals in the black sands, zircon and monazite.The results obtained by the different methods, particularly aeroradiometry, distinguished six zones of rich mineral content, either directly on the beach or inland. Three of these zones (I, IV, and VI) can be related to three former branches of the River Nile, the Bucolic, Mendesian, and Saitic branches mentioned by Ball (1942). The other three zones (II, III, and V) could also be sites of deposition along old shorelines at the outflows of extinct ancient branches that have not been previously reported.The study revealed that there is a general direct correlation between the aerial data and that from ground radiometry and zircon and monazite tenors. Moreover, zircon showed a stronger correlation than monazite with both aerial and ground radioactivity. As in the case of Rosetta black-sand beach deposits (El Shazly et al., 1977), it was observed that zircon content decreases from west to east while the change in monazite content is almost insignificant.
