IN THE ESNA-IDFU REGION, NILE VALLEY, EGYPT 49 



Hassan 1956 ; Youssef 1957 ; Hermina, Ghobrial & Issawi 1961). Its planktonic 

 Foraminifera correlate it with the type Maestrichtian (Hofker 1962a), with the 

 Maestrichtian rocks below the type Danian (Berggren 1962 and Troelsen 1955) and 

 with the Maestrichtian in various parts of the world (Text-fig. 6). However, the 

 disconformity separating the Maestrichtian Sharawna shale formation from the 

 overlying Paleocene was always overlooked in the past, and the stratigraphical 

 sequence as well as the chronological succession of life in this part of the geological 

 column was never completely understood. As a result, various authors (e.g. Hume 

 1911, 1912, followed by most stratigraphers) tended to lump the Sharawna shale 

 formation, either partly or completely, together with the overlying Lower Owaina 

 shale member under the term " Lower Esna shales ", and considered these shales 

 with the overlying chalk bed as of Danian age. On the other hand, Nakkady (1959) 

 described as " Lower Esna shale " in the Kharga Oasis, a succession of Paleocene 

 shales which is here considered to be identical with the Lower Owaina shale 

 member. 



Thus, it is evident that the classification of the Esna shale into lower and upper 

 units as suggested by Hume (1911, 1912) and followed by various authors is incorrect, 

 and should be replaced by the classification suggested here. Again, it is worth 

 noting that the term Dakhla shale, introduced by Ghorab (1956) as a member of his 

 Esna formation, to substitute for the " Ashen grey paper shales " of some authors, 

 or the " Lower Esna shale " of others, and which was raised to formational rank by 

 Said (1961) is also incorrect. The " Dakhla shale " as originally designated and 

 interpreted in the present study, includes the Maestrichtian " Sharawna shale ", the 

 conglomerate separating it from the overlying Paleocene " Owaina shale ", and the 

 lower part of the latter formation. These varied lithological and palaeontological 

 units which are clearly separated by a marked break, cannot be treated as one 

 formation. Thus the term " Dakhla shale " is here dropped and the classification 

 of the Esna group into a lower " Sharawna shale " formation and an upper " Owaina 

 shale " formation is suggested. 



The " Sharawna shale " is equated on lithological and palaeontological grounds 

 with similar successions in both the Dakhla and the Kharga Oases (Western Desert) 

 and in the Kosseir and Safaga areas (Red Sea Coast). It is proved to have a wide 

 geographical extent in Egypt, although it becomes gradually more calcareous when 

 followed northwards until completely replaced by chalk. 



(4) The Owaina Shale Formation. 

 This formation is considered to be of Paleocene age, for the following reasons: 



(a) It disconformably overlies the Maestrichtian " Sharawna shale ", and 



underlies the Lower Eocene " Thebes formation ". 



(b) Its base is marked by a conglomerate with reworked Maestrichtian, and 



Danian faunas, and its upper part coincides with the top of the Globorotalia 

 velascoensis Zone which is taken to mark the end of the Paleocene in vari- 

 ous parts of the world (see Text-fig. 6). 



