Messinian events in the Black Sea

Abstract

Past hydrological interactions between the Mediterranean Sea and Black Sea are poorly resolved due to complications in establishing a high-resolution time frame for the Black Sea. We present a new greigite-based magnetostratigraphic age model for the Mio-Pliocene deposits of DSDP Hole 380/380A, drilled in the southwestern Black Sea. This age model is complemented by 40Ar/39Ar dating of a volcanic ash layer, allowing a direct correlation of Black Sea deposits to the Messinian salinity crisis (MSC) interval of the Mediterranean Sea. Proxy records divide these DSDP deposits into four intervals: (i) Pre-MSC marine conditions (6.1-6.0 Ma); (ii) highstand, fresh to brackish water conditions (~6.0-5.6 Ma); (iii) lowstand, fresh-water environment (5.6-5.4 Ma) and (iv) highstand, fresh-water conditions (5.4-post 5.0 Ma). Our results indicate the Black Sea was a major fresh-water source during gypsum precipitation in the Mediterranean Sea. The introduction of Lago Mare fauna during the final stage of the MSC coincides with a sea-level rise in the Black Sea. Across the Mio-Pliocene boundary, sea-level and salinity in the Black Sea did not change significantly.