THE GEOLOGY OF EGYPT. 



IN the account of the geology of the Sahara which ap- 

 peared in " Science Progress" for July, 1895, tne de- 

 scription of the Egyptian deposits was necessarily very 

 cursory. But Egypt is geologically a part of the Sahara, 

 and no account of the latter can be complete without 

 including the former. The present article, therefore, is 

 practically a continuation of the previous one. 



The literature of Egyptian geology is so extensive that 

 it would be impossible, even if it were desirable, to attempt 

 here a complete bibliography of the subject. I have, there- 

 fore, quoted only those works to which it is necessary to 

 refer in order to give a fairly complete description of the 

 geology of this region. Even yet by far the most detailed 

 general account of the country is to be found in Zittel's 

 Libysche W'uste (34). But this was published in 1883, and 

 since that time much geological work has been done in 

 Egypt, especially in Lower Egypt and in the Arabian 

 Desert. References to the most important papers which 

 have appeared since the publication of Zittel's work will be 

 found in the bibliography at the end of this article. 



Egypt, in the ordinary sense of the term, includes the 

 region which lies between the sandy part of the Libyan Desert 

 on the west and the Red Sea on the east, and which ex- 

 tends from the shores of the Mediterranean to the " Second 

 Cataract ' near Wadi Haifa. It is divided into two parts 

 by the Nile ; and excepting the delta and the valley of that 

 river, it is for the most part a barren waste of mountain and 

 plateau. West of the Nile we have the Libyan Desert, and 

 east of it the so-called Arabian Desert extending to the Red 

 Sea. 



North of Cairo the greater part of the country is low- 

 lying, and much of it is of recent origin ; but south of that 

 town there is on each side of the river an extensive plateau 

 of Eocene rocks. The western plateau is the larger and 

 more monotonous in character, and extends as far south as 



