Physiography, Climate and Soil-Vegetation Relationships

Abstract

In early geological time, Egypt (as well as other countries of North Africa) was invaded on several occasions by the Sea of Tethys. This old geologic sea, probably of the Precambrian Era, is the antecedent of the Mediterranean Sea and has always encroached on Egypt from the north. This means that Egypt’s past land—sea distribution has not always been the same as that of today. During late geological periods, the land of Egypt was uplifted, such uplift leading to a retreat of the Sea of Tethys. The retreating sea must have left behind sediments and remnants of the living organisms which it contained. Proof of this is the great quantity of sea shells spread over the surface of the Egyptian inland deserts, in places far from the sea and at elevations much higher than present sea level (Abu Al-Izz, 1971).