Genesis of Iron Oxides and Ferruginous Oolites in the Coniacian - Santonian Sequence of the Abu Zenima Area, Sinai, Egypt PDF

Keywords

Egypt, Iron oxide, Sinai

Abstract

The pyritic, glauconitic, and dolomitic facies within the Coniacian- Santonian sequence of the Abu Zenima area, west-central Sinai, Egypt, display characteristic post-depositional, chemical, mineralogical and textural changes. These changes are mostly attributed to bacterial activity and weathering. The studied microfacies are represented by thin layers of ferruginous pyrite-biomicrite, ferruginous glauconitic oolite, mottled dolostone, and ferruginous glauconitic quartz arenite. The ferruginous ooids are generated in place from the weathering of glauconite grains, whereas the mottled character of the dolostone is produced by the oxidation of ferrous iron released from ankerite and glauconite grains by weathering. The ferruginous materials are composed mainly of hematite. goethite and lepidocrocite.