PALYNOSTRATIGRAPHICAL STUDY OF SOME CRETACEOUS ROCKS (APTIAN– LOWER CENOMANIAN) OF NABIL-1 WELL, NORTH WESTERN DESERT, EGYPT

Abstract

A palynological analysis has been carried out on the Lower–Middle Cretaceous (Aptian-lower Cenomanian) rock units encountered in the subsurface section of the Nabil-1 well, north Western Desert of Egypt. Twenty four ditch cutting samples have been analyzed palynologically and produced 40 species, which allow recognizing six informal palynomorphs zones restricted to northern Western Desert ranging from early Aptian to Cenomanian age. The identified zones are CE.1 Elaterosporites klaszii Acme zone, CE.2 Trilobosporites laevigatus interval zone, AL.1 Araucariacites australis Acme zone, AL.2 Concavissimisporites punctatus interval zone, AL.3 Concavissimisporites sp. sensu Deaf 2009 interval zone, AP.1 Murospora florida Acme zone and AP.2 Afropollis operculatus Acme zone. The erected palynozones are not only applicable to the western part of the Western Desert, but valid to the north Western Desert as well. They are correlated with well-documented zonations established for the same interval from other sites in the north Western Desert of Egypt and outside in North Africa. The palaeoenvironmental settings ranged between arid to semi arid in the lower Cenomanian to humid in the Albian and Aptian with marine conditions that varied between near shore to open marine environment.