S UPPER CRETACEOUS-LOWER TERTIARY FORAMINIFERA 



bottom, rapid dispersal by ocean currents, and their ability to select the depth and 

 therefore to some extent the temperature they prefer while living, their relatively 

 rapid evolutionary development, and their buoyancy which allows further current 

 dispersal even after death of the organism, certain planktonic forms supply the best 

 available evidence for world-wide correlations ". Thus, in the present study both 

 the macrofauna and the co-existent planktonic Foraminifera are identified and are 

 used to interpret the stratigraphy of the region. While the macro-fossils were found 

 to be restricted in their geographical distribution and only useful for local correlation, 

 the planktonic Foraminifera provided a sound basis for the zonation of the succession 

 and its correlation with the type sections and with the known planktonic foraminifer- 

 al zones elsewhere. Moreover, the stratigraphical ranges of the macrofossils could be 

 established in the light of the planktonic foraminiferal zonation, thus ending a long 

 controversy about their ranges. 



However, despite the remarkable value of planktonic Foraminifera, the strati- 

 graphical and taxonomic confusion surrounding many of the species, has almost 

 masked their importance. The rich planktonic foraminiferal populations encount- 

 ered in the Upper Cretaceous-Lower Tertiary succession of the Esna-Idfu region have 

 helped to clear up this confusion and to establish the morphological characteristics 

 and the stratigraphical range of each of these species. This wealth of planktonic 

 Foraminifera, which probably marks the succession as the richest ever recorded, 

 provided an excellent opportunity for a detailed study of inter- and intraspecific 

 variation among large species populations and for a study of the phylogenetic 

 relationships between the various forms recorded. The main part of this work is 

 therefore devoted to a detailed study of the important members of the planktonic 

 Foraminifera, many of which are here described for the first time from Egypt, 

 North Africa and the Middle East. 



Location and geological setting of the esna-idfu region. This region lies 

 in Upper Egypt between latitudes 24°58'oo" N and 25 ° 2o'oo"N, and longitudes 32 ° 

 20 'oo" E and 33 ° 05 '00" E. It includes part of the Nile Valley between the towns of 

 Esna and Idfu, and extends eastwards and westwards into the vast deserts on either 

 side, covering an area of about 3,200 square kilometres (Text-fig. 1). 



The region is bounded on the west and northwest by the Lower Eocoene limestone 

 scarp (El-Sinn) which forms the eastern edge of the famous limestone plateau of the 

 Western Desert. On the south and east, it is bounded by the Nubia sandstone 

 plateau, which extends in both directions outside the region to the basement complex, 

 at a distance of about 75 kms. to the east and about 100 kms. to the south. 



This Nubia sandstone plateau extends into the Esna-Idfu region constituting 

 most of its eastern, southeastern and southern parts, dipping gently to the north- 

 west to be progressively overlain by the Sibaiya phosphate, the Esna shale and 

 finally by the Thebes limestone and calcareous shale. These four main lithological 

 units, which are clearly recognizable in the field, together constitute the Upper 

 Cretaceous-Lower Tertiary succession of the Esna-Idfu region. They form the main 



