484 THE GEOLOGY OF THE NILE VALLEY. 



Above Abou Simbel this overlies the sandstone in curious forms, 

 simulating black coral or sponge. 



Unmistakable lavas, however, do occur in the desert within one 

 day's journey of the Nile, both east of Minieh and west of Assiout. 

 There is then some real evidence of volcanic action in this region, 

 and the occurrence of sulphates mentioned above may be thus 

 explained. 



The sandstone has been deposited over the basalt at Abou Sir, 

 near Wady Haifa, and the river has worn it away again, leaving 

 the basalt bare ; in several places the basalt is seen sticking up 

 through the sandstone. 



The principal lines of junction of all the main formations appear 

 to run from S.S.E. to N.N.W. 



Discussion. 



The Peesident observed that Englishmen in Egypt enjoyed at 

 present very good opportunities of doing geological work, but it 

 was a matter of regret that they did not pay more attention to the 

 literature. Many of the facts noted in the present paper had been 

 mentioned in the appendix to Sir William Dawson's 'Modern 

 Science in Bible-lands,' and the silicated deposits had been discussed 

 by Zittel and others and ascribed by Zittel to the action of 

 fumaroles. Sir W. Dawson referred to the sandstones, which though 

 carbonaceous are not Carboniferous . The Authors raised many 

 chemical points of interest, and one of the Authors was a chemist 

 who, he believed, had recently described a new element discovered 

 by the other Author in one of the dry valleys dealt with in the 

 present communication. The information concerning the region 

 south of Assouan was of considerable interest, though the state- 

 ment that the granite was intrusive in the sandstone was open to 

 doubt. 



Mr. ToPLEY and Mr. Exjtley also spoke. 





