The Messinian Salinity Crisis in Mallorca: New insights for a Western Mediterranean stratigraphic scenario

Abstract

The Messinian Salinity Crisis (MSC) was an extraordinary geological event that affected the whole Mediterranean region, as well as global marine circulation between 5.97 and 5.33 Ma. In the Mediterranean, the crisis was mainly characterized by isolation from the Atlantic Ocean, resulting in a new hydrological budget leading to the accumulation of large amounts of evaporites and large-scale erosion of its margins. The nature of the majority of the evaporites and erosional surfaces is still unknown, thus representing a challenge which forms the subject of debate in the scientific community.The Neogene Mallorca basins (Balearic Islands) are well situated to provide a stratigraphic record which expresses the sequence of events related to the MSC, being especially suitable for testing possible geological models or scenarios. New research on the island of Mallorca provides data about the MSC and Zanclean reflooding in the central part of the Western Mediterranean (Balearic Basin), with obvious repercussions for both academia and industry.The main aim of this study is to describe the features which characterize sedimentation during the Miocene-Pliocene transition on the island of Mallorca, to establish how this stratigraphic record relates to the different proposed MSC scenarios for the whole of the Mediterranean. In this regard, a stratigraphic analysis was carried out on a total of 100 exposures and boreholes corresponding to the Neogene basins of Mallorca. The results indicate that, on the island of Mallorca, the development of the MSC is most consistent with models that represent the main phase of desiccation occurring after the accumulation of marginal evaporites (Primary Lower Gypsum), the Terminal Carbonate Complex and the Lago Mare deposits.