542 Hugh J. L. Beadnell — The Fayum Depression. 



Eecent and I Alluvial soil, blown sand, and high-level lacustrine sands 

 Pleistocene. / and clays. 



j Shell-borings on exposed rocks. 

 Pliocene. > Fossiliferous deposits of Sidmant. 



j Gravel terraces. 

 Lo-\vER Oligocene \ 



AND \ 6. Fluvio -marine Series (Gebel el Qatrani beds). 



Upper Eocene. ) 



!4. Qasr el Sara Series (Carolia beds). 

 3. Birket el Quruu Series (Operculina-Nummulite beds). 

 2. Eavine Beds (fish-scale marls). 

 1 . Wadi Eayan Series {Nummulites gizehensis beds) . 



1. Wadi Katan Series. 



The wadis of Eayan and Mouailla, on the southern side of the 

 Fayum depression, are cut out in the clays and limestones of this 

 group, equivalent to part of the Lower Mokattam of the Nile Valley. 

 The uppermost bed of limestone, characterized by the profusion of 

 the large foraminifer Nummulites gizehensis, forms a considerable 

 part of the floor of the depression west of the Fayum cultivation, 

 stretching from Gebel Eayan northwards to the foot of Gar el 

 Gehannem, 28 kilometres west of the western extremity of the 

 Birket el Qurun. 



2. Eavine Beds. 



This series, estimated at 25 metres thick, consists of gypseous 

 clays and white marly limestones, and is met with bordering the 

 cultivated land on the east, west, and north sides. The same beds 

 are frequently exposed in the deep ravines of El Butts and El Wadi 

 which intersect the cultivation. The beds yield shell-impressions 

 of Lecla, Tellina, etc., with fish-teeth and numerous scales. No 

 vertebrate remains have as yet been obtained from this or the 

 underlying series. Beds of this group form the base of the island 

 ' Geziret el Qorn ' and the lower part of the northern shore of the 

 Birket el Qurun. 



3. Birket el Qurun Series. 



The beds of this group, some 60 metres thick, form the main 

 part of the escarpment immediately overlooking the north shore of 

 the lake. The series appears to be the equivalent of the upper 

 part of the white beds (limestones) of Gebel Mokattam, although 

 lithologically there is considerable difference. Certain beds of the 

 series are characterized by the abundance of two foraminifera, 

 Nummulites Fraasi and Operculina discoidea. A well - marked 

 molluscan fauna is also present, and cetacean and fish remains 

 are not uncommon. The series is well seen in the desert separating 

 the Fayiim and Nile Valley, along the northern boundary of the 

 cultivation and of the lake, and westwards in the cliff's to the 

 outlying hill-mass of Gar el Gehannem. 



In the northern part of the Fayum the series is divisible by 

 a very constant well-marked bed of hard sandstone, which almost 

 invariably weathers out into a number of huge globular masses. 

 The lower beds are seen in the island of Geziret el Qorn, and from 



