Upper Palaeocene-lower Eocene succession of the Kharga Oasis, Western Desert, Egypt: Foraminiferal biostratigraphy and sequence stratigraphy

The present study provides a better understanding of the nature of the upper Palaeocene-lower Eocene succession within the framework of the sequence stratigraphy. It is based on the qualitative and quantitative analyses of the foraminiferal assemblages of the Esna and El-Rufuf formations at the Kharga Oasis, Western Desert. Seven planktonic foraminiferal zones were recognized; P4c and P5 zones of the late Palaeocene (Thanetian) age and E1-E5 zones of the early Eocene (Ypresian) age. The Palaeocene/Eocene (P/E) boundary is recorded at the base of the Dababiya Quarry Member of the Esna Formation that coincides with the P5/E1 zonal boundary. A minor hiatus has been documented across this boundary equivalent to the missing lowermost part of the Dababiya Quarry Member. The foraminiferal investigations (e.g., planktonic percentage, benthic foraminifera cluster analyses, diversity, and abundance) as well as field work and the lithofacies examination have been integrated to subdivide the studied succession into five third-order depositional sequences separated by five sequence boundaries. These sequences are primarily formed in response to the greater impact of the global sea-level oscillations, as well as the partial effect of the regional tectonics, which may be related to the influence of the Syrian Arc system. The regional tectonics led to occasional discrepancies in the timing and extent of some changes in the relative sea-level and mismatching of some boundaries.