The Cenomanian-Turonian succession of Abu Darag area is subdivided, lithostratigraphically, into the Galala Formation (Cenomanian–Early Turonian) and the Umm Omeiyid Formation (? Middle-Late Turonian). Biostratigraphically, three ammonite zones have been recognized in the studied section; Acanthoceras sp. Zone (Middle Cenomanian), Neolobites vibrayeanus Total Range Zone (early Late Cenomanian), and Choffaticeras segne Total Range Zone (Early Turonian). The corresponding zones based on other macrofossils include from older to younger: • Ceratostreon flabellatum – Rhynchostreon suborbiculatum Acme Zone, • Hemiaster (Hemiaster) cubicus Total Range Zone, • Ilymatogyra africana-Heterodiadema libycum-Hemiaster (Mecaster) pseudofourneli Assemblage Zone, • Rudists-corals-coralline sponge Assemblage Zone, and • Hemiaster (Mecaster) heberti turonensis-Coenholectypus turonensis Total Range Zone. The integration between the proposed ammonite and non-ammonite zones as well as local and interregional correlation with other well dated zonal schemes has been discussed. The Cenomanian/Turonian boundary is placed at the base of the Choffaticeras segne Zone. |
