The Esna 

 Group 



254 UPPER CRETACEOUS-LOWER TERTIARY FORAMINIFERA 



VI. SUMMARY AND CONCLUSIONS 



A detailed examination of the various outcrops in the Esna-Idfu region has led to 

 the classification of its Upper Cretaceous-Lower Tertiary succession into five 

 formations and eight members, three formations and seven members of which are 

 here described for the first time. These are as follows : 



TOP E. The Thebes Limestone and Calcareous Shale Formation. ) Th T K 

 8. The Thebes Limestone Member. > „ ^ 



7. The Thebes Calcareous Shale Member. J " 



I). The Owaina Shale Formation. 



6. The Upper Owaina Shale Member. 

 5. The Middle Owaina Chalk Member. 

 4. The Lower Owaina Shale Member. 

 'n/wwvxa/'n/wwvxa/ DISCONFORMITY 'n/wa/'v/w/w/w/wi 

 C. The Sharawna Shale Formation. 



3. The Upper Sharawna Shale Member. 

 2. The Middle Sharawna Marl Member. 

 1. The Lower Sharawna Shale Member. 

 B. The Sibaiya Phosphate Formation. ) The Nubia 



A. The Nubia Sandstone and Variegated Shale Formation, j Group 



These rock units were used as a basis for the detailed mapping of the region. 

 This mapping has proved the existence of a distinct stratigraphical break between 

 the Maestrichtian and the overlying Paleocene. In spite of repeated emphasis 

 on the absolute conformity of the succession by previous authors, a conglomerate 

 with reworked Upper Cretaceous fossils was clearly observed in the field and was 

 found to mark a distinct faunal break in the succession. The detailed lithostrati- 

 graphy and the maps are presented elsewhere (El-Naggar, in manu), but small 

 scale reproductions of these maps are, however, given here to show the distribution 

 of the various rock units and the locations of the sections examined. 



The succession was first zoned on the basis of its macrofossils. One hundred and 

 forty two species were identified. Consideration of their ranges led to the recognition 

 of five faunal zones and three subzones, in addition to a zone devoid of macrofossils 

 near the top and a non-fossiliferous zone at the base of the succession. These are as 

 follows : 



TOP 7. The Lucina thebaica Zone. 



6. A Zone devoid of macrofossils. 

 5. The Ostrea hypoptera Zone. 

 4. The Caryosmilia granosa Zone, 

 vvvwwv^vvuvvvvwvvvvv DISCONFORMITY vvwma^wwwvvwwwi 

 3. The Pecten (Chlamys) mayereymari Zone. 

 (c) The Libycoceras berisensis Subzone. 

 (b) The Pecten (Chlamys) mayereymari Subzone. 

 (a) The Terebratulina gracilis Subzone. 

 2. The Lopha villei Zone. 

 1. A non-fossiliferous Zone. 



