482 Sir J. W. Dawson — Geology of the Nik VaUeij. 



Sinaitic region, which Hull now proposes to call the " Desert Sand- 

 stone," are of Carboniferous age. 



The Lepidodendron Mosaicnm of Salter and other plants sub- 

 sequently found are certainly Carboniferous forms, and the marine 

 fossils, the first of which were found by Bauerman in the associated 

 limestone, are now recognized as of the same age. In Egypt fossils 

 of this age have not yet been found ' in the Nubian sandstone ; but 

 there are indications, as above stated, that this is divisible into two 

 members, the upper of which may be Lower Cretaceous, while the 

 lower may possibly be Palceozoic. In this case, as all these sand- 

 stones are products of the decay of the crystalline rocks, and are un- 

 disturbed, they may possibly represent a shallow sea continuing 

 throughout the Carboniferous and early Mesozoic ages, and receiving 

 the coarser debris washed down from the older formations. As 

 already stated, the sandstones of the lignitiferous zone of the Lebanon 

 are probably somewhat higher in the Cretaceous series than the 

 Upper Nubian sandstone of Egypt and Southern Palestine, and are 

 probably Cenomanian. Possibly the beds with vegetable remains 

 which have been reached by boi'ing near Edfou may be its repre- 

 sentatives. 



4. The middle and later part of the Cretaceous was in this region 

 a time of submergence. But in the Nile valley, and generally in 

 the vicinity of the older rocks, the amount and duration of the 

 submergence were less than farther to the north and east, so that 

 the Cretaceous limestones of Palestine are of much greater volume 

 than those of Egypt. It is to be observed, however, that if the 

 Lignitiferous sandstone of the Lebanon is correctly referred by 

 Fraas to the upper part of the Cenomanian, then a period of shallow- 

 water and land conditions must have recurred in that region, and 

 interrupted the marine conditions. 



5. The Cretaceous depression continued throughout the Eocene 

 period, and the great thickness of the limestones of this age in 

 Egypt, and the moderate depths which they indicate, would seem 

 to testify to a slow and long-continued depression, which does not 

 seem to have prevailed to the same extent in Syria. Hence the 

 Eocene deposits of the latter country are much less important. 



6. The first important elevation seems to have occurred at the 

 close of the Eocene, so that the beds of that age furnished the soils 

 on which the NicoUce, Pines and Palms of the Gebel Ahmar sand- 

 stones flourished ; and the areas of marine Miocene are very limited 

 in Egypt, and apparently wanting in Syria, indicating that the 

 region had already assumed a continental character. 



7. The Pliocene age was probably still more continental, and it is 

 possible that in this age the Nile emptied into a great inclosed saline 

 basin, of which the deposits now constituting the higher portion of 

 the Isthmus of Suez may be a monument, though it is also possible 

 that they may belong in whole or in part to the second continental 

 period of the Post-Glacial age. However this may be, it seems 

 certain that Egypt shared in the great submergence of the Pleistocene 



1 Unless the Arauearioxylon ^gyptiacum should be regarded as Palaeozoic. 



