الفهرس 
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Abstract
Episodic sea level fluctuations are indicated by rapid facies changes within the Oasis Member. Variability in its thickness from one locality to the other may indicate deposition on an irregular basin. The presences of current induced structures indicate high energetic, turbulent conditions. The presence of some beds demarcated on top by lag deposits and a trace fossil suite of the firm ground Glossifungites ichnofacies indicates occasional reduced sedimentation rate and reworking. This member is moderately fossiliferous with oysters, pectinids, echinoids, other bivalves and gastropods. This fossil assemblage and their skeletonzoans indicate shallow marine conditions. Absence of fauna in some beds may indicate stressed conditions. The Siwa Escarpment Member represents a transgressive phase with flourishing of most faunal groups. The dominance of oysters in addition to pectinids, and echinoids, with their skeletozoans, substantiates the dominance of low energy, shallow marine conditions with low sedimentation rate. Nearly the same conditions of the Escarpment Member prevailed during the deposition of the El-Diffa Member. Cyclical changes of fossiliferous with poorly fossiliferous beds, and the presence of gastropods may indicate stressed conditions and fluctuating salinity.