Decoding sea surface and paleoclimate conditions in the eastern Mediterranean over the Tortonian-Messinian Transition

New sedimentological, micropaleontological and geochemical data from the Upper Miocene pre-evaporitic se dimentary sequence of the Faneromeni section (Crete Island, eastern Mediterranean) revealed a stepwise re striction of the Mediterranean Sea preceding the Messinian Salinity Crisis (MSC), which was modulated by sedimentary cyclicity responding to orbital parameters. This cyclicity is manifested by lithological alternation from laminated to indurated homogeneous marls and clayey limestones, and covers the Tortonian-Messiniai Transition (TMT; 7.6-6.7 Ma). This time window covers the successive closure of the marine Mediterranean Atlantic gateways, which culminated in the onset of the MSC. In the present study, we present the first evident, for changes in the upper water column reflected by sea surface temperature (SST) and salinity (SSS) variation that correlate with pronounced paleoclimatic fluctuations. Planktonic foraminiferal isotopes, in combinatioi with paired mixed layer Sr/Ca-derived SST data, reveal that the very warm late Tortonian interval has bee( followed by a strong long-term cooling (similar to 10 parts per thousand) and desalination (similar to 10 parts per thousand) trend during the earliest Messinian attributed to the paroxysmal phase of the so-called siphon event. In particular, the climate shift that occurre( at the end of a global carbon isotope (delta C-13) decrease suggests that changes in the carbon cycle were instrumenta in driving late Miocene climate dynamics (cooling and aridity) in the progressively isolated easten Mediterranean Sea. The observed salinity variability during this time interval also provides further insight about seasonal freshwater inputs and gives new support to the much-debated hydrologic regime (linear salinit' increase vs step-function evolution with strong salinity fluctuations) preceding the deposition of evaporites. Th, novel methodology of foraminiferal Sr/Ca paleothermometry and results of this study could have numerou potential applications to other regions and relevant extreme geological events. Therefore, in the near future w, expect this approach to add important new information to our understanding of Neogene climates.