Early-Middle Cenomanian Foraminifera And Ostracods From Bb-80-1 Well, Gulf Of Suez, Egypt: Biostratigraphy, Palaeoecology, And Palaeobiogeographic Significance

The present study concentrates on the foraminiferal and ostracod assemblages recorded from the subsurface Galala Formation in the northern part of the Gulf of Suez, Egypt. This investigation yielded 37 foraminiferal species (belonging to 26 genera, 10 superfamilies, and 14 families) and 25 ostracod species (belonging to 14 genera, 6 families, and 2 superfamilies). The foraminiferal assemblage is characterized by the dominance of typical Cenomanian agglutinated species with some planktonic species. The integration between benthic and planktonic foraminiferal species has led to the recognition of five proposed local biozones namely: Flabellammina alexanderi-Daxia cenomana Zone, Thomasinella fragmentaria Zone, Ismailia neumannae Zone, Nezzazata simplex-Trochospira avnemelichi Zone, and Hedbergella delrioensis-Praeglobotruncana delrioensis Zone. On the other hand, the stratigraphic distribution of the recorded ostracods resulted in the identification of four local biozones, involving Glenocythere reticulata Zone, Veeniacythereis streblolophata Zone, Spinoleberis yotvataensis Zone, and Cytherella-Ovocytheridea Zone. The recorded foraminifera are classified into five morphogroups and submorphogroups. Based on these morphogroups and other palaeoecological factors, five ecozones covering the Cenomanian are also distinguished. The palaeobiogeographical outline of the studied ostracod assemblages was carried out with the assistance of multivariate analyses (principal component analysis and Q-mode cluster analysis). The results point out that, there are two distinguished groups; one of them represents the South Tethyan Province (STP), including Morocco, Algeria, Tunisia, and Egypt. The second group represents the Middle East Province (MEP), including Oman, Lebanon, Saudi Arabia, Kuwait, and Iran. The strong affinity between the two provinces indicates a direct communication along the Southern Tethyan margin during the Cenomanian and enhanced marine faunal exchange.