Petrography and depositional environment of the Paleocene-Eocene sequence in Hammam Faraun, southern Sinai, Egypt

The Paleocene- Eocene succession in the Hammam Faraun area consists of eight conformable formations; namely (from older to younger): the Esna Shale, Thebes, Darat, Samalut, Khaboba, Mokattam, Tanka and Tayiba. Generally, carbonates constitute the major part of the studied sequence which contains also chert and shale interbeds. Petrographically, these rocks are represented by the microfacies associations: micrite, foraminiferal biomicrite, pel-foraminiferal biomicrite, pel-algal foraminiferal biomicrite, sparry micrite, microsparite, foraminiferal pel-biomicrosparite, dolomicrosparite, pel-foraminiferal biosparite, pel-algal-foraminiferal biosparite and microcrystalline quartz (chert). Calcite dominates in the limestones, while quartz and dolomite are the most abundant constituents in the chert and dolomitic limestone interbeds; respectively. Hematite, halite and gypsum exist in varying proportion in the studied rocks. Shale intervals are occasional and consist mainly of montmorillonite, kaolinite and illite. The studied Paleocene- Eocene sequence accumulated in shallow to deep neritic marine environments during a regressive phase of the sea characterized by pronounced sea-level oscillations. The original textural and compositional characteristics of the studied carbonates were modified by several diagenetic possesses represented by recrystallization (neomorphism), cementation, glauconitization, dolomitization and silicification.