Evolution of carbonate platforms in the northeast Red Sea during the last 23 million years.

The Midyan Peninsula between the northern Red Sea and Gulf of Aqaba is the only place along the Red Sea where Lower to Middle Miocene syn-rift sedimentary strata (Aquitanian to Langhian) are continuously exposed, including exceptionally preserved carbonate platforms. We selected four focus areas onshore and one offshore in the Duba Basin to explore the variations in platform morphology, structural setting, spatial distribution, and carbonate factory in the northeast Red Sea. By integrating surface observations, geophysical and well data, and strontium (Sr) isotope stratigraphy, we situate these platforms in the tectonic and paleogeographic context of the opening of the northeastern Red Sea rifted margin. The findings document a transition from mollusk-dominated ramps in the early syn-rift stage (~ 23-21 Ma) to coral- and algal-dominated fringing platforms on normal fault footwalls and delta-top platforms during the rift climax and late syn-rift stages (~ 21-14 Ma). Carbonate production ceased during the Middle to Upper Miocene (~ 13-6 Ma), likely due to very high salinity conditions. New dating indicates that carbonate production resumed at the end of the Miocene (~ 5.5 Ma). Thick, aggrading coral-algal platforms-attached and detached-developed, with their morphology strongly shaped by salt tectonics.