Evolution river nile sudan

The Integrated Nile

There are two theories in relation to the age of the integrated Nile. The First One is that the integrated drainage of the Nile is of young age, that the Nile basin was formerly broken into series of separate basins, only the most northerly (the Proto Nile basin) feeding a river following the present course of the Nile in Egypt and in the far north of the Sudan (Said, 1981). Said (1981) stress the fact that Egypt itself supplied most of the waters of the Nile during the early part of its history. The other theory is that the drainage from Ethiopia via rivers equivalent to the Blue Nile and the Atbara/ Takazze flowed to the Mediterranean via the Egyptian Nile since well back into Tertiary times (Williams and Williams, 1980). Salama, 1987 suggested that during the Tertiary there were a series of separate closed continental basins, each basin occupying one of the major Sudanese Rift System; Mellut Rift, White Nile Rift, Blue Nile Rift, Atbara Rift and Sag El Naam Rift (Salama, 1987). Mellut Rift Basin is nearly 12 km deep at its central part. This rift is possibly still ACTIVE, there are reported tectonic activity in its northern and southern BOUNDARIES. The Sudd swamps which forms the central part of the Basin is possibly still subsiding. The White Nile Rift System; although shallower than Bahr El Arab, it is AbOUT 9 km deep. The Blue Nile Rift System, geophysical exploration in this area estimated the depth of the sediments to be 5-9 km. These basins were not interconnected except after their subsidence ceased and the rate of sediment deposition was enough to fill up the basins to such a level that would allow connection to take place. The filling up of the depressions led to the connection of the Egyptian Nile with the Sudanese Nile, which captures the Ethiopian and Equatorial head waters during the latest stages of tectonic activities of Eastern, Central and Sudanese Rift Systems (Salama, 1997). The connection of the different Niles occurred during the cyclic wet periods. The River Atbara overflowed its closed basin during the wet periods which occurred about 100 000 to 120 000 yrs B.P. The Blue Nile was connected to the main Nile during the 70 000 – 80 000 yrs B.P. wet period. The White Nile system in Bahr El Arab and White Nile Rifts remained a closed lake until the connection of the Victoria Nile some 12 500 yrs B.P.

References:

Said, R. (1981).The geological evolution of the River Nile Springer-verleg

Salama, R.B. (1987). The evolution of the River Nile, The buried saline rift lakes in Sudan. J. African Earth Sciences. 6(6). Pp 899-913.

Salama, R.B. (1997). Rift Basins of Sudan. African Basins, Sedimentary Basins of the World. 3. Edited by R.C. Selley (Series Editor K.J.Hsu) p. 105-149. ElSevier, Amsterdam.

Williams, M.A.J. and Williams, F. (1980). Evolution of Nile Basin. In M.A.J.Williams and H. Faure (eds),The Sahara and the Nile. Balkema, Rotterdam, pp.207-224.