The Geological Evolution of the River Nile in Egypt

Abstract

Sediments form one of the chief sources of information; they show great changes in the river valley since its ‘down cutting’ through earlier rocks in the Upper Miocene. Five river phases succeeded each other: the ‘Eonile’ in the Upper Miocene, ‘Paleonile’ in Upper Pliocene, and the ‘Proto- Pre- and Neo-Nile’ in the Pleistocene. These phases were separated by ‘episodes’, with th e riv er declining or even ceasing its flow for reasons of tectonic and climatic changes. The ultimate origin of the Nile valley is difficult to ascertain completely because the original beds are buried under deep sediments and disturbed by tectonic ‘blocks’ and faults, crossing or lying parallel to the present valley. More geophysical and geodetic work would be required; some clues have been provided by numerous bore-holes all over Egypt and the offshore areas, in search for oil and water.

EDITOR. Under this title R. Said, of the Geological Survey of Egypt, has summed up what is known at present about the development of the Nile system in Egypt (in press, 1975). Previously, in his Geology of Egypt (1962) he has brought together the results of both the work by others and his own. From these sources an overall and very broad sequence of events has been compiled.