IN THE ESNA-IDFU REGION, NILE VALLEY, EGYPT 19 



wrongly considered to mark the base of the Maestrichtian, is here assigned to the 

 Upper Campanian, as the species, although rare in the Aquitaine Basin in general, 

 has been recorded in the type Campanian only (Jeletzky 1951 and Mrs. M. Seronie- 

 Vivien, personal communication). Moreover, in spite of the accumulated indisput- 

 able evidence for the Upper Cretaceous age of the type Maestrichtian, Hofker, in 

 several publications (1955-62), has argued for the time-stratigraphic equivalency of 

 the type Maestrichtian and the type Danian. Hofker's claims were discussed by 

 Loeblich & Tappan (1957ft) and Berggren (1962) who showed clearly that the true 

 stratigraphical relationship between the Danian and the Maestrichtian stages is one 

 of superposition and not lateral equivalence. 



Stratigraphical Position of the Danian 



Desor (1846) introduced the Danian as the youngest stage of the Cretaceous 

 system, typified by the succession of the Cerithhim, bryozoan, coralline and cocco- 

 lithic limestones, which disconformably overlies the Senonian white chalk of Denmark. 

 He considered these Danian deposits as equivalent to the so-called " pisolitic lime- 

 stone " which similarly overlies the Senonian white chalk disconformably at Laver- 

 sines and Vigny in the Paris Basin, and which were generally considered, at that 

 time, to be of Upper Cretaceous age. In his definition of this new stage he stated : 

 " M. Desor pense des lors qu'il faut envisager le calcaire de Faxoe, la craie corallienne 

 et le lambeau pisolithique de Laversine et de Vigny, comme un etage particulier de la 

 craie, le plus recent de tous, ainsi que l'avait propose M. Elie de Beaumont ; mais il 

 ne saurait y comprendre les terrains a Nummulites, qu'il envisage comme etant d'une 

 epoque plus recente. M. Desor propose d'appeler cet etage terrain danien, parce 

 qu'il est surtout developpe dans les iles du Danemark. Ainsi que l'avait propose 

 M. Graves, il est probable qu'on devra y rapporter par la suite le terrain de Maes- 

 tricht ". 



Six years later, d'Orbigny (1852) described the fauna of the type Danian, and in 

 agreement with Desor, he considered it as the youngest stage of the Cretaceous 

 system, but clearly distinguished it from the underlying Maestrichtian. Since then 

 the same concept has been automatically followed by most stratigraphers, in spite 

 of the doubts about the true Cretaceous nature of the type Danian fauna. Indeed, 

 the Tertiary affinities of this fauna have been pointed out as early as 1823 by Forch- 

 hammer, (see Rosenkrantz i960), long before the establishment of the term, and 

 later by Starkie Gardner (1884) and a few other authors. 



On the other hand, Desor, in his original definition of the term, mentioned that the 

 beds of Maestricht may possibly be included within his Danian stage. This vague 

 statement led various authors to extend the Danian downwards in the succession 

 to include the Maestrichtian and even the Campanian, in spite of the marked strati- 

 graphical break between the Danian and the underlying strata in both the type 

 region of Desor and in other parts of the world. Thus, Mayer-Eymar (1872) consid- 

 ered the Danian to include the Campanian of Coquand, the Maestrichtian of Dumont 

 and the Danian of Desor, while Hebert (1875) extended the Danian downwards to 



