in the esna-idfu region, nile valley, egypt 47 



(3) The Sharawna Shale Formation. 



The Sharawna shale formation is considered to be of Maestrichtian age for the 

 following reasons : 



(a) It conformably overlies the Upper Campanian " Sibaiya phosphate forma- 



tion ". 



(b) Eleven meters above the base of the formation, a marly band flooded with 



Terebrahtlina gracilis Schlotheim, Isocardia (Isocardia) chargehensis Mayer- 

 Eymar and Pecten (Chlamys) mayereymari Bullen-Newton, as well as with 

 several other macro- and microfossils, was discovered. Terebrahtlina 

 gracilis marks the base of the type Maestrichtian in Holland, and of the 

 Maestrichtian rocks in Belgium and in the Aquitain Basin of France (the 

 Maestricht-Committee of the Sub-Committee on the Upper Cretaceous 

 Stratigraphic Commission, International Geological Congress ; in Reiss 

 1962). It also marks the base of the Maestrichtian in Germany (Schmid, 

 Hiltermann & Koch 1955) and in Palestine (Parnes 1956). 



(c) The lower part of the Sharawna shale formation i.e. the Lower Sharawna 



shale member, is flooded with a rich planktonic foraminiferal fauna 

 (Text-figs. 9-1 1, 16) which substantiates its Lower Maestrichtian age and 

 correlates it with the Lower Maestrichtian in various parts of the world 

 (Text-fig. 6). 



This fauna characterises a particular zone which is here termed the Globotruncana 

 fornicata Zone. Noteworthy among the species characteristic of this zone are 

 members of the Globotruncana fornicata group and most of the members of the 

 Globotruncana stuarti group, the last representatives of which mark the Lower 

 Maestrichtian in most parts of the world, (e.g. Cita 1948 ; Tilev 1951, 1952 ; 

 Drooger 1951 ; Bolli 1951, 19570 ; Noth 1951 ; Sigal 1952 ; Dalbiez 1955 ; Gandolfi 

 1955 ; Pozaryski & Witwicka 1956 ; Bronnimann & Brown 1956 ; and Pessagno 

 i960). 



Also of importance in this zone are : Globotruncana area, G. gagnebini, G. fareedi, 

 G. havanensis and Rugoglobigerina rugosa, which are known to be restricted to the 

 Maestrichtian in different parts of the world (see Bronnimann & Brown 1956 ; 

 Tilev 1951, 1952 ; Bolli 1957a ; Berggren 1962, etc.), as well as Globotruncana 

 leupoldi, G. aegyptiaca aegyptiaca, G. tricarinata tricarinata and G. ventricosa, which 

 characterize older strata, but range through the Lower Maestrichtian. 



(d) The " Middle Sharawna marl member " is marked by the first appearance of 



Globotruncana gansseri ganserri Bolli at its base, and this, together with 

 its other subspecies, floods the whole unit and the lower part of the overlying 

 shale member, constituting a particular faunal zone, here termed the "Globo- 

 truncana gansseri zone ". Analysis of the stratigraphical ranges of the 

 various members of this zone, substantiates its Middle Maestrichtian age 

 and correlates it with corresponding strata elsewhere. Globotruncana 

 gansseri gansseri Bolli, the index fossil of the zone, was recorded as 



