Palynology, palynofacies and petroleum potential of the Upper Cretaceous–Eocene Matulla, Brown Limestone and Thebes formations, Belayim oilfields, central Gulf of Suez, Egypt

• Most of the studied Turonian–Eocene deposits are immature – marginally mature.
• They are capable of generating mix oil and gas of kerogen Type-II and II/III.
• The Matulla Formation is palynologically dated as Turonian–Santonian.
• It was deposited under marine dysoxic–anoxic to proximal suboxic–anoxic shelf.
• The Brown Limestone and Thebes formations are deposited under similar conditions.

Palynological, palynofacies and organic geochemical results of 46 samples retrieved from the Upper Cretaceous – Eocene Matulla, Brown Limestone and Thebes formations, Belayim oilfields, central Gulf of Suez, Egypt are presented. The two latter formations are not dated palynologically as their lithology is not promising for palynological yield. However the Matulla Formation is dated as Turonian–Santonian age, based on the combined evidence of pollen and dinocysts.Palynofacies analysis carried out under both transmitted and fluorescent microscopy indicated that both the Thebes and Brown Limestone formations are deposited under a distal suboxic–anoxic environment. On the other hand, the Turonian–Santonian Matulla Formation supported the existence of a marginal marine deposition under dysoxic–anoxic basin to proximal suboxic–anoxic shelf environments. Rock-Eval pyrolysis and TOC results indicated that most of the studied formations are thermally immature to marginally mature and have a good petroleum potential. They are organically-rich in both oil- and gas-prone kerogen Type-II and II/III, deposited under marine reducing conditions favorable for hydrocarbon generation and expulsion.