Palustrine Limestone in an Extensional Northern Duwi basin, West of Quseir, Red Sea, Egypt

Yousuf, Reham; Mahran, Tawfik; Hassan, Abdullah M.

doi:10.21608/sjsci.2023.199839.1069

Palustrine Limestone in an Extensional Northern Duwi basin, West of Quseir, Red Sea, Egypt

Document Type : Regular Articles

Authors

Geology Department, Faculty of Science, Sohag University, Sohag 82524, Egypt.

10.21608/sjsci.2023.199839.1069

Abstract

The northern Duwi basin is an extensional rift basin formed in the initial NW Red Sea rifting stage. This study focuses on the Late Oligocene palustrine limestone of the Sodmin Formation in the northern Duwi half-graben basin. Field and petrographic studies indicate that the Sodmin Formation consists of four stratigraphic units (Unit I- IV), which exhibit pedogenic features suggesting the deposition in a low gradient shallow lake environment where changes in water level from an overfilled to a balanced-fill and finally to an underfilled lake basin resulted in an extensive emergence. Allogeneic controls such as tectonics and climate strongly influenced the palustrine system evolution. Tectonics determined the variations in thickness and lithofacies distribution where the basin was affected by the basin-bounding fault segments and suggested that the extensional fold-bound syncline was eventually locally breached by surface-breaking faults, resulting in the establishment of a half-graben. Paleoclimate influenced the palustrine facies variations and determined sub-aerial exposure periods. The palustrine limestone deposition took place under sub-humid to semi-arid and arid conditions. Source rock could also have a role in the evolution of the drainage pattern. A depositional evolutionary model was constructed depending on the lithofacies architecture of the palustrine sequence and the influence of the early formed propagating fault segment and the associated hanging-wall depocenters during the initial stages of rifting.

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