50 UPPER CRETACEOUS-LOWER TERTIARY FORAMINIFERA 



(c) Its basal part contains a rich fauna of the Globorotalia compressajGlobigerina 



daubjergensis Zone which correlates it with the type Danian (Bronnimann 

 1953 ; Reichel 1953 ; Troelsen 1957 ; Loeblich & Tappan 1957a, b ; and 

 Berggren 19606, 1962) and with the Danian elsewhere (Bolli 19576, 19596 ; 

 Loeblich & Tappan 1957a, b ; Bolli & Cita 1960a, b ; Olsson i960 ; Hay 

 i960 ; Leonov & Alimarina 1961). 



The abundance of Globorotalia compressa (Plummer) in the Danian part 

 of this succession, which is very much reduced in thickness (maximum of 

 about 17 m. only), clearly proves that it represents the Upper Danian only 

 (see Berggren 19606, 1962), and that both the Lower and Middle Danian are 

 missing. 



(d) This Upper Danian part is followed by a zone devoid of both Danian index 



species and of those characteristic of the Upper Paleocene. This zone is 

 marked by the first appearance of the truncated Globorotalia species and 

 by a flood of the Globorotalia angidata group. It is here named the Globo- 

 rotalia angulata Zone and is considered, on the basis of its stratigraphical 

 position, to be of Middle Paleocene age. 



(e) The middle and upper members of the Owaina shale formation coincide with 



the Globorotalia velascoensis Zone which is of Upper Paleocene age as 

 discussed above. However, it is worth noting that the first appearance of 

 Globorotalia velascoensis does not precisely coincide with the base of the 

 intercalated chalk bed (the Middle Owaina chalk member), but occurs 

 slightly below it in a band of calcareous shale with thin chalky bands 

 which is considered transitional to the Middle Owaina chalk member. 



(f) The Owaina shale formation is overlain by the Globorotalia wilcoxensis 



Zone of Lower Eocene age (see Text-figs. 5 and 6). 



Thus it is evident that the Owaina shale formation is of Paleocene age, that its 

 basal part corresponds to the Upper Danian in its type section and elsewhere, and 

 that its upper part correlates with the known Upper Paleocene in various parts of 

 the world. However, in view of the confusion about the planktonic foraminiferal 

 content of the various stages of the Paleocene (see p. 25 et seq.), the author decided 

 not to use the known Paleocene stage names (e.g. Montian, Thanetian, Landenian, 

 Seelandian, Ilerdian) 4 , but to divide the Paleocene into three major divisions, lower, 

 middle and upper, on the basis of its three planktonic foraminiferal zones, as discus- 

 sed above (see pp. 24-31) and summarized on Text-figs. 5 and 6. 



The planktonic Foraminifera of the Owaina shale formation correlates it with 

 known Paleocene sections elsewhere in the world (Text-fig. 6), and its macrofossils 

 clearly relate it to similar successions in Egypt (Zittel 1883 ; Quaas 1902 ; Wanner 

 1902 ; Oppenheim 1902 ; Hume 191 1 ; Cuvillier 1937a, 6 ; Youssef 1955, 1957 ; 

 Hassan 1956 ; Hermina et al., 1961. However, the misunderstanding of the true 

 nature of the Cretaceous-Tertiary contact in Upper Egypt introduced by Zittel (1883) 



4 See footnote 2 



