Late Miocene Mediterranean desiccation: topography and significance of the `Salinity Crisis' erosion surface on-land in southeast Spain

Abstract

Abstract The result of sea level fall at the margins of the Mediterranean during the Late Miocene `Salinity Crisis' was the creation of an extensive erosion surface. However, the shape of this `Salinity Crisis' unconformity reflects local factors and in turn significantly determined local conditions during subsequent reflooding. At Sorbas, in southeast Spain, erosional overdeepening of a pre-existing basin during drawdown created a depression over 200 m deep with an incised floor patterned by 30-m-deep gullies. During reflooding this semi-enclosed palaeovalley temporarily became a barred basin in which gypsum was deposited. These Sorbas evaporites thus resulted from local basin sculpture. Diverse local effects elsewhere during drawdown and reflooding account for marked stratigraphic variations that continue to complicate recognition and correlation of the `Salinity Crisis' in marginal successions. The drawdown erosion surface is itself the key indicator of this important event in marginal Mediterranean basins.