--> Abstract: Sedimentary Environments and Depositional Characters of the Middle-Upper Eocene Succession in the Fayum Depression, Egypt; #90063 (2007)

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Sedimentary Environments and Depositional Characters of the Middle-Upper Eocene Succession in the Fayum Depression, Egypt

 

Abdel-Fattah, Zaki A.1, Murray, K. Gingras1, Michael, W. Caldwell1, S. George Pemberton1 (1) Alberta University, Edmonton, AB

 

Eocene strata in Egypt are extremely fossiliferous and have good reservoir potential. Two middle-upper Eocene successions exposed in outcrop in the Wadi El-Hitan (Whale Valley) and Qasr El-Sagha areas of the Fayum depression were examined, Egypt. Based on sedimentological and ichnological data, six facies associations (FA) are identified. The middle Eocene Gehannam Formation is represented by a stacked facies succession of thoroughly-burrowed sandstones, bedded mudstones, and muddy sandstones with mangrove roots of FA (1a, 2a, 2b), respectively. Highly burrowed sandstones and sandstones with coquina of FA (1b, 3) comprise the entire middle-upper Eocene Birket Qarun Formation. The interbedded sandstones and coquina of FA 4a and the carbonaceous sandy shale of FA 4b represent the lower Temple Member. Finally, the cross-bedded sandstones of FA 5 and the sandstones/mudstones of FA6a-f form the upper Dir Abu Lifa Member of the upper Eocene Qasr El-Sagha Formation. Both tectonics and relative sea-level fluctuations play an important role in the distribution of these facies associations and their corresponding depositional environments. The defined facies associations record a gradual shallowing. The overall receding of the Tethys from south to north resulted in an upward transition of the depositional environment from a large open marine bay or gulf covering the southern and central Fayum (during the middle Eocene), to marginal-marine environments that prevailed in the central and northern Fayum areas (during the late Eocene). Facies Association 1 records a distal open marine bay or gulf that is succeeded by a bay-margin environment (FA2) and is topped by a costal/ravinement setting (FA3). Upwards, marginal-marine lagoonal/bay parasequences (FA4) are followed by regressive, deltaic distributary channels (FA5). The capping unit, Facies Association 6, records an estuarine-channel depositional environment.

 

AAPG Search and Discover Article #90063©2007 AAPG Annual Convention, Long Beach, California