Dimensions of the Atlantic-Mediterranean connection that caused the Messinian Salinity Crisis

The connecting strait is assumed to behave in a similar way as existing straits, such as the Strait of Gibraltar or the Bosphorus. A salinity crisis in an enclosed basin results, when its connection to the open ocean is highly restricted. A strait needs to be relatively shallow, narrow and/or long in order to result in exchange fluxes that are of around 25% or less of the exchange at the Strait of Gibraltar today. Considering the evaporite deposits together with global sea-level variations we estimate the cross section of a strait responsible of the MSC to have a minimum depth of 30-45 m and a maximum width of 0.7-2 km for lengths in the range up to 500 km. These dimensions are consistent with only a few of the Miocene corridors identified. The calculations are extended to explore the implications for sedimentary structures on the corridor floor.