Late Tortonian-early Messinian stepwise disruption of the Mediterranean-Atlantic connections: constraints from benthic foraminiferal and geochemical data

摘要

Late Miocene marine land-based sections in the Mediterranean area contain important information on the prelude to the Messinian salinity crisis (MSC). Integrated (bio-, magneto-, tephra- and cyclo-) stratigraphy allows for bed-to-bed correlations of sections throughout the Mediterranean and its borderlands, and enables correlation with extra-Mediterranean (Atlantic) sites. Benthic foraminiferal and geochemical data from five sections were compared to literature data and indicate that: (a) restriction of the Mediterranean from the Atlantic Ocean started during the late Tortonian, (b) the continuous development towards the MSC started as early as ～7.2 Ma in the deeper parts of the basis and was enhanced by astronomical forcing and (3) the onset of the MSC must have been to a large extent related to differential vertical movements at the Betic and Rifian corridors. The Miocene connections between the Mediterranean and the Atlantic.