256 UPPER CRKT ACEOUS-LOWER TERTIARY FORAMINIFERA 



3. The Sharawna Shale formation is of Maestrichtian age. It conformably 

 overlies the Sibaiya Phosphate formation, and is separated from the overlying 

 Paleocene Owaina shale formation by a distinct break. It is characterized by one 

 major macro-fossil zone, the Pecten (Chlamys) mayereymari Zone, which contains 

 three subzones as mentioned above. It is divided on the basis of its lithology into 

 three distinct members : the Lower Sharawna Shale member, the Middle Sharawna 

 Marl member and the Upper Sharawna Shale member. These correspond to the 

 Terebratnlina gracilis Subzone, the Pecten (Chlamys) mayereymari Subzone and the 

 Libycoceras berisensis Subzone in the macrofossil zonation respectively. They also 

 correspond to the Globotruncana fornicata Zone, the lower part of the Globotruncana 

 gansseri Zone and both the upper part of the latter zone and the Globotruncana 

 esnehensis Zone in the planktonic foraminiferal zonation. These three planktonic 

 foraminiferal zones are taken to represent the Lower, Middle and Upper Maestrich- 

 tian and are correlated with corresponding zones in other parts of the world. 



4. The Mesozoic-Cainozoic boundary in the Esna-Idfu region is marked by a 

 distinct break and by a well developed conglomerate as mentioned above. It has 

 been shown that this break is widespread throughout the country and exists in 

 regions where conformity has hitherto been assumed. 



5. The disconformity which marks the top of the Maestrichtian Sharawna Shale 

 formation indicates the passage of a relatively long period of time, and represents 

 the uppermost Maestrichtian as well as the Lower and Middle Danian. 



6. The Owaina Shale Formation is of Paleocene age. It disconformably overlies 

 the Maestrichtian Sharawna Shale and includes three members : The Lower Owaina 

 Shale member, the Middle Owaina Chalk member and the Upper Owaina Shale 

 member. Its Lower and Middle members coincide with both the Caryosmilia granosa 

 and the Ostrea hypoptera Zones respectively, while its upper member is devoid of 

 macrofossils except for rare dwarfed forms seen only in washed residues. On the 

 basis of its planktonic Foraminifera, the Owaina Shale formation is divided into the 

 three zones and four subzones listed above. The Globorotalia compressa. /Globigerina 

 daubjergensis Zone which coincides with the basal part of the Lower Sharawna 

 Shale member, is also known to characterize the Danian in its type section and in 

 other parts of the world. However the abundance of G. compressa clearly indicates 

 that this part of the succession corresponds to the Upper Danian only, and proves that 

 both the Lower and Middle Danian are missing. The G. compressajG. daubjergensis 

 Zone represents the Lower Paleocene (or Danian), while the G. angulata and the 

 G. velascoensis Zones represent the Middle and Upper Paleocene respectively. 



7. The various stage and substage names of the Paleocene such as the Montian, 

 Thanetian, Sparnacian, Landenian, Heersian, Seelandian, etc., could not be applied 

 because the relationship between one stage and another is not clearly understood, 

 and the proper position of each in Paleocene stratigraphy is not known. 



8. The Maestrichtian Sharawna Shale and the Paleocene Owaina Shale forma- 

 tions, together constitute a major group, commonly known as the Esna Shale. 

 Previous classifications of this group into lower and upper Esna Shale, or into 

 Dakhla and Esna shales are incorrect. 



