310 PROF. E. HULL ON THE GEOLOGY OF THE NILE VALLEY. [May 1896^ 



the "Wealden area, once the course of the river had been selected as 

 the land emerged from the ocean in Miocene times, that course was 

 never abandoned. The physical features of the region between the 

 Nile and the Red Sea are quite inconsistent with such an hypo- 

 thesis as that referred to. 



3. Faults. 



Besides a depression along the general course of the Nile Valley 

 in the surface of the Eocene and Cretaceous beds, which must have 

 guided the original course of the river northward, faults appear to 

 have played an important part. They have been noticed by Dawson, 1 

 E. H. Johnson and H. D. Richmond, 2 Lyons, 3 and others. That 

 which follows the line of the valley above Cairo has long been 

 known. 



Another remarkable fault is shown on the right bank about 

 5 miles below Earshut, following the course of the stream, with 

 the downthrow on the western side, along which the beds are 

 highly tilted and bent. A third case at Gebel Ain, above Luxor, 

 is remarkable for the high angle at which the beds are seen to dip 

 (fig. 1). This is visible in the left bank of the river, and appears to 

 follow its course in that locality. 



Eig. 1. — Sketch at Gehel Ain, shoiving beds of limestone highly tilted 



ne of fault. 



[The escarpment of Eocene limestone is in the background to the right.l 



I refer to these cases merely in order to show that the line of 

 erosion of the primaeval Nile was sometimes directed by the disloca- 

 tions of the strata ; but some of the faults are transverse to those 

 which run parallel to the course of the stream, such as that at 

 Haghaghah. 4 



1 ' Modern Science in Bible Lands/ Appendix, 1888. 



2 Quart. Journ. Geol. Soc. vol. xlviii. (1892) p. 482. 



3 Ibid. vol. 1. (1894) p. 541. 



* Described by Johnson and Richmond. 



