IN THE ESNA-IDFU REGION, NILE VALLEY, EGYPT 61 



sion studied. It is characterized by the flood of the various subspecies of the 

 Globotruncana fornicata group which is taken as the index species for the zone. 



The top part of the G. fornicata Zone is marked by the diappearance of G. fornicata 

 fornicata, G. fornicata mananrensis, G. fornicata globulocamerata, G. contusa scutilla, 

 G. contusa witwickae, G. mariai and G. tricarinata tricarinata, as well as by the first 

 appearance of G. gansseri gansseri, G. ganserri subganserri, G. ganserri dicarinata, 

 G. lugeoni, G. aegyptiaca duwi, G. conica, G. contusa contusa, G. contusa patelliformis, 

 G. esnehensis, G. rosetta pettersi, G. sharawnaensis, G. stuarti parva, G. subcircumnodi- 

 fer, G. sp. Rugoglobigerina glaessneri, R. macrocephala, R. pennyi, R. pustulata, and 

 Trinitella scotti. 



It is also characterized by the presence of G. adamsi, G. aegyptiaca aegyptiaca, 

 G. area, G. cf. convexa, G. fareedi, G. fundiconulosa, G. gagnebini, G. cf gagnebini, 

 G. leupoldi, G. mariei, G. orientalis, G. rosetta rosetta, G. stuarti stuarti, G. stuarti 

 stuartiformis , G. stuarti subspinosa, G. tricarinata columbiana, G. ventricosa, G. 

 havanensis, Rugoglobigerina loetterli, R. rugosa, Hedbergella hessi compressiformis, 

 H. hessi hessi, H. mattsoni, H. monmouthensis, and H. petaloidea. 



The G. fornicata Zone characterizes the " lower Sharawna shale member " and 

 coincides with the Terebratulina gracilis Subzone of the macrofossil classification. 

 Both its planktonic foraminiferal and macrofossil content as well as its stratigraphi- 

 cal position (conformably overlying the Upper Campanian Lopha villei Zone) suggest 

 a Lower Maestrichtian age as summarized above (see pp. 46-49). 



4. The Globotruncana gansseri Zone. 



This represents the second planktonic foraminiferal zone from the base of the 

 succession upwards. It coincides with both the " Middle Sharawna marl member " 

 and the lower part of the overlying " Upper Sharawna shale member ". It is charac- 

 terized by the first appearance and the flood of the various subspecies of the G. gans- 

 seri group, which is taken as the index species for the zone. Its base is marked by the 

 top of the underlying G. fornicata Zone, and its top by the diappearance of G. area, 

 G. bahijae, G. conica and G. sp. as well as by the great reduction in the number of 

 individuals of the G. gansseri group and the flooding of G. esnehensis, and by the 

 first appearance of R. rotundata. 



It is also characterized by the presence of Globotruncana aegyptiaca aegyptiaca, 

 G. arabica, G. area, G. bahijae, G. cf. convexa, G. fareedi, G. fundiconulosa, G. gagnebini, 

 G. gansseri gandolfii, G. leupoldi, G. mariei, G. orientalis, G. rosetta rosetta, G. 

 stuarti stuarti, G. stuarti stuartiformis, G. stuarti subspinosa, G. youssefi, G. 

 havanensis, Abathomphalus intermedia, Hedbergella hessi compressiformis, H. hessi 

 hessi, H. monmouthensis, H. petaloidea, Rugoglobigerina glaessneri, R. loetterli, R. 

 macrocephala, R. pennyi, R. pustulata, R. rugosa, and Trinitella scotti, as well as by the 

 rare occurrence of the following forms at its base : G. adamsi, G. fornicata ackermanni, 

 G. fornicata cesarensis, G. cf. gagnebini, G. tricarinata colombiana, G. ventricosa and 

 Hedbergella mattsoni. 



