ABSTRACT Extensive deposition of thick marine evaporites occurred during the middle and late Miocene in the Gulf of Suez rift basin, yet their origin remains controversial, particularly regarding marine connectivity, brine sources, and climatic controls. In the St. Paul area, at the western rift margin, stacked, shallowing‐upward cycles of shale, mudstone, and evaporite grade landward into conglomerate and sandstone of proximal fan facies. A detailed sedimentological and sequence stratigraphic study offers new insights into the evolution of these Langhian–Serravallian marginal marine evaporites and their basinal equivalents, clarifying the timing of restriction events and proposing viable models for their accumulation. The evaporites, mainly epigenetic anhydrite, occur as nodular forms with chicken‐wire and enterolithic textures, indicative of deposition in saline mudflats under a hot, arid climate. This marine‐fed, siliciclastic‐rich sabkha flat lacks a modern analog due to its uncommon mud matrix. Periodic continental flooding disrupted the sabkha mudflat, leading to the deposition of laminated and fanned gypsum in ephemeral saline pans. The stratal architecture of the evaporites and associated sediments reveals three depositional sequences, each with a lower retrograding deep subtidal shale and basal channelled sandstone, and an upper prograding shallow subtidal to intertidal siliciclastic mud and supratidal evaporites. Sabkha and salina evaporites mark the late highstand facies, while lowstand evaporites formed in the basin centre when it became isolated and hypersaline due to evaporative drawdown. Three major marine flooding events from the Mediterranean had occurred during the Langhian–Serravallian, prior to complete basin isolation from the north. Each event culminated in extensive evaporite accumulation as the basin became temporarily isolated. Rift‐related tectonics, global cooling, glacio‐eustasy, and changes in basin connectivity were key drivers of temporary restrictions, while arid climate controlled brine concentration. These findings resolve some long‐standing debates on the origin of the Gulf of Suez evaporites and their connection to the northern Mediterranean source during the Miocene.
Mounir El-Azabi (Thu,) studied this question.