Notices of Memoirs — H. T.Ferrar — Loess Deposits, Egypt. 421 



(2) Note on the Occukrence of Loess Deposits in Egypt and its 

 Bearing on Change of Climate in Kecent Geological Times.' 

 By H. T. Ferrae, M.A., F.G.S. 



AT a recent meeting of tlie Association Dr. Hume and Mr. Craig 

 submitted the view that there liad been no change, except that 

 of gradual desiccation, in recent geological times in Egypt. Since 

 their paper -was published, evidence that the change of climate has 

 not been uniform has been recorded from neighbouring countries. 

 The following short paper is intended to show how JEolian desertic 

 deposits may be interstratified between freshwater beds without any 

 change of climate. 



In the northern delta of Egypt are great stretches of flat land a few 

 feet above sea-level. These areas are covered by ordinary Nile 

 alluvium and remain damp during the winter months but dry in 

 summer. Owing to the evaporation which takes place during the 

 spring and early summer, soluble salts accumulate at or near the 

 surface of the soil, rendering it incoherent and powdery. Winds are 

 now able to lift and trans[)ort this material until it is arrested by the 

 roots of halophyte plants or other obstacles. Here also are deposited 

 the dead shells of helices, and occasionally also the remains of land 

 animals, sucli as the jackal, rat, bird, lizard, or snake, whicli have 

 been seen frequenting dust-dune areas. In fact, the dust dunes of 

 Northern Egypt, known as Kardud to the inhabitants, are local 

 deposits of Loess. 



A depression of the land of only a few feet, and such as that which 

 has taken place since Roman times in Egypt, would cause another 

 fluviatile layer containing the common shell Cyrena fluminalis or 

 a lacustrine bed to be superimposed upon them. It is thus manifest 

 that a desertic deposit interstratified between two freshwater beds is 

 not necessarily a proof of change of climate. 



(3) The Physiography of Arid Lands (as illustrated by Desert 

 Egypt). By W. F. Home, D.Sc, F.R.S.E., A.K.S.M., Director 

 Geological Survey of Egypt. 



rpHE characters of an arid land cannot be separated from its past 

 I history, and in Egypt five physiographic features of first 



importance have to be considered. Tliese are — 



1. A belt of deep impressions in the extreme west, the famous 

 Oases. 



2. The broad waterless expanse of the Western or Libyan Desert, 

 to the west of the Nile, and the corresponding limestone plateau 

 region (the Maaza Limestone Plateau) to the east of the river. 



3. The Nile Valley with its Delta. 



4. The Wilderness of the Bed Sea Hills and Sinai witli its rugged 

 mountains and tortuous valleys. 



5. The Red Sea and its narrow prolongations, the Gulfs of Suez 

 and Aquaba, together with the coastal plains. 



Each of these divisions requires separate treatment. The paper 



' By permission of the Director-General of the Egyptian Survey Department. 



