﻿Vol. 6l.] CKETACEOUS SYSTEMS OP THE NILE VALLEY. '375 



UPPER CRETACEOUS. 



Danian. — 3. White, brown-weathering (sometimes pink), fissile, shaly 

 marly limestone and chalk, with veins of celestine. 

 Ostrea aff. vesiculates. This bed will probably be found 

 to be identical with the Eckinocorys-Ch&lk. 



20 metres = 66 feet, 



4. Green and blue, laminated, shaly clays, with a white marly 



limestone-band near the centre containing Ostrea vesicu- 

 laris, Ehynchonella sp. nov. 1 , and Baculitcs. The equiva- 

 lent of the ' ashen-grey clays ' of the Southern Oases. 



100 metres = 328 feet. 



5. Pect en-Mavis. White marly limestone, passing up into 



grey marls and marly clays with red ferruginous bands, 

 crowded in places with Pecten farafrensis, fish-remains, 

 and shell-casts 8 metres = 26 feet. 



6. Laminated grey and iroristained shales. 



30 metres = 98 feet, 

 Beds 5 & 6 correspond to the ' Exogyra-Senes' of the 

 Southern Oases. 

 ■Campanian. — 7. Hard oyster-limestone, with intimately-associated bone- 

 and-coprolite bed. Oysters of Ostrea- For gemotti, 0. -larva, 

 and 0.- Villei types. Hard, fissile, splintery, siliceous lime- 

 stone at the base 4 metres — 13 feet. 



This bed corresponds to the Ptychoceras-~Limestone of 

 Wadi Hammama, etc., and the hard limestone capping 

 the bone-bed series in the Dakhla Oasis. 2 

 8. Sandy clays, shales, and sandstones. 



45 metres = 148 feet, 

 (Upper beds of the Nubian Series.) 



With regard to the Esna Shales, in the foregoing section I have 

 ■classified them as passage-beds. There is no doubt that they 

 bridge over the period which elapsed between the deposition of the 

 Cretaceous white chalk and the incoming of the Nummulitic sea. 

 In some places, as at Thebes, the Esna-Shale fauna appears to have 

 a considerable affinity with that of the ' ashen-grey clay-series ' ; 

 in others, for instauce Farafra Oasis, the presence of bands contain- 

 ing Operculina, etc. links them to the Eocene. Par more detailed 

 work than has yet been carried out is necessary, before the age of 

 this variable series in the different areas can be satisfactorily 

 established, and consequently, for the present, it is preferable to 

 refer to them as passage-beds. 



(6) General Conclusions. 



At the Paris International Geological Congress of 1900, 1 brought 

 forward 3 evidence from the Baharia Oasis and Abu Eoash to show 

 that there was a marked unconformity between the Cre- 

 taceous and Eocene systems in the northern part of 



1 This is the first record of the occurrence of the genus Ehynchonella in 

 Egypt. 



* H. J. L. Beadnell, 'Dakhla Oasis' Egypt, Geol. Surv. Report (Cairo, 1901) 

 pp. 82, 83, etc. 



3 ' Decouvertes geologiques recentes dans la Vallee du Nil et le Desert 

 Libyen' Compte-rendu du \iii nie Congr. geol. internat, 1900 (Paris, 1901) 

 pp. 839-53. 



