Deciphering salt tectonic deformation patterns in the Eastern Mediterranean: Insights from the Messinian evaporite in the Herodotus Basin

Abstract

Salt-bearing basins are commonly deformed in response to gravity mechanisms (gliding and spreading) and regional tectonics. However, these processes often overlap both in time and space that challenges the understanding of the main causes for salt flow and overburden deformation. In this study, salt-related deformation is investigated at the eastern part of the Herodotus Basin in the Eastern Mediterranean. Deformation in this area is associated with the flow of Messinian salt (evaporite) that was deposited during the Messinian Salinity Crisis (MSC). The MSC sequence is relatively young and is characterized by a thin overburden, and as such provides a unique opportunity to explore key controls of salt-related deformation. High-quality 2D seismic reflection data from the broader area of the carbonate platform of the Eratosthenes Continental Block, which constitutes the natural boundary between the Herodotus Basin to the west and the Levantine Basin to the east, reveal significant thickness variations of the MSC sequence and the overlying Plio-Quaternary clastic sediments. Five distinct salt-tectonic structural provinces characterize the study area that depicts different salt-related deformation styles. Furthermore, the morphology of the Eratosthenes Continental Block plays a critical role in controlling salt flow. Finally, the compressional thickening of the Messinian salt driven by the combination of gravity gliding and spreading results in the absence of a bathymetric step on the seafloor at the western side of the Eratosthenes Continental Block.