Desiccation of the Red Sea basin at the start of the Messinian salinity crisis was followed by major erosion and reflooding from the Indian Ocean

The extent of desiccation in deep enclosed basins has been debated for over 50 years. Here we combine seismic, biostratigraphic, and strontium isotope data to document a deep desiccation event across the Red Sea basin that ended 6.2 million years ago. This event exposed the seafloor to erosion, forming an angular unconformity that decapitated Middle Miocene salt diapirs and truncated Late Miocene layered anhydrites. The unconformity is overlain by Messinian-Pleistocene pelagic carbonates and reef platforms, reflecting an abrupt shift from evaporitic to open marine conditions. The desiccation was likely triggered by the onset of the Messinian salinity crisis in the Mediterranean and it ended with a flood from the Gulf of Aden, which incised a 320 km long canyon through the volcanic Mandab and Hanish sills. This desiccation marks the final disconnection of the Red Sea from the Mediterranean and its initial connection to the Indian Ocean. The Red Sea underwent complete desiccation prior to the Messinian Salinity Crisis, but this event ended rapidly about 6.2 million years ago as a result of a catastrophic flood in the Gulf of Aden, according to an analysis of high-resolution seismic data, biostratigraphy, and strontium isotope dating.