Notices of 3Iemoirs — H. J. L. Beadnell — Geohgi/ of Egypt. 23 



They have no alternations of hard and soft beds, and, so far as I have 

 seen, no repetition of beds by folding. The evidences of movement 

 on their flanks, if any, are not more than one would expect from the 

 vertical pressure of a more or less plastic shale upon what is at least 

 a less plastic limestone. 



I admit fully that there are abundant evidences in the district of 

 faulting, of great pressure, and quite likely of overthrusts ; but to 

 say that these have given to these rocks a change of chai'acter, or are 

 responsible for the order of their succession, appears to me to be 

 invoking an unnecessarily powerful but yet inadequate force. Sucli 

 thrust-planes as are implied would meet the geologist in the field 

 at every turn, and force themselves into recognition. They would 

 admit of easy mapping, and no statement of their existence would 

 be complete without some such systematic recognition. 



2^0Ticss OIF nycEnycoiiRS- 



I. — On some Eecent Geological Discoveries in the Nile 

 Valley and Libyan Desert.' By Hugh J. L. Beadnell, 

 F.G.S., F.R.G.S. 



IN this paper the author draws attention to some interesting 

 discoveries made by him during the last three or four years 

 while attached to the Geological Survey of Egypt. AVhen the 

 latter Survey was established in 1896 the publications and maps, 

 both geological and geographical, of the Eohlfs Expedition of 

 1873-74: still remained the only source of information on the greater 

 part of Egypt. 



In his geological reports Zittel, the geologist of the Eohlfs 

 Expedition, calls special attention to the absence of any uncon- 

 formity between the Cretaceous and Eocene deposits, in fact 

 mentioning this as one of the most important results obtained. 

 More extended researches have, however, enabled the author " to 

 bring forward incontestable evidence from at least two areas in the 

 Libyan Desert, namely, Abu-Eoash, near Cairo, and Baharia Oasis, 

 that instead of this perfectly gradual petrographical and palteonto- 

 logical passage, undisturbed by any unconformity, from the upper- 

 most marine Chalk into the oldest Tertiary beds, thei'e is as a matter 

 of fact a strongly marked unconformity, representing a long lapse 

 of time in the process of sedimentation. During this period the 

 Cretaceous was elevated into land, often witli intense folding and 

 faulting, and underwent considerable denudation before subsidence 

 led to the entire or partial submergence of the area below the sea, and 

 allowed the deposition of successive beds of Eocene in a markedly 

 overlapping manner." 



The accompanying table is compiled chiefly from the work of 

 Professor Zittel and the Geological Survey of Egypt. 



1 Abstract of a paper read (with the permissiou of Captaia 11. G. Lyons, R.E., 

 F.G.S., the Director-General of the Ej,n'ptiau Geological Survey) before the Inter- 

 national Geological Congress at Paris, 1900. 



