Mediterranean–Black Sea gateway exchange: scientific drilling workshop on the BlackGate project

• Published in: Scientific drilling (Hokkaido, Japan) Vol. 31; pp. 93 - 110
• Main Authors: Krijgsman, Wout, Vasiliev, Iuliana, Beniest, Anouk, Lyons, Timothy, Lofi, Johanna, Tari, Gabor, Slomp, Caroline P, Cagatay, Namik, Triantaphyllou, Maria, Flecker, Rachel, Palcu, Dan, McHugh, Cecilia, Arz, Helge, Henry, Pierre, Lloyd, Karen, Cifci, Gunay, Sipahioglu, Özgür, Sakellariou, Dimitris
• Format: Journal Article
• Language: English
• Published: Gottingen Copernicus GmbH 28-10-2022; Copernicus Publications
• Subjects: Animal migration; Anoxia; Anoxic sediments; Archives & records; Basins; Brackish water; Carbon cycle; Catchment area; Climate change; Climate system; Conferences, meetings and seminars; Connectivity; Cycles; Drilling; Drilling and boring; Earth; Eustatic changes; Fault zones; Freshwater; General circulation models; Holocene; Hydrology; Influence; Inland water environment; Interglacial periods; Lacustrine sedimentation; Land bridges; Marl; Messinian; Miocene; Ocean floor; Pliocene; Quaternary; Salinity; Sapropels; Sciences of the Universe; Sea level changes; Stratigraphy; Ventilation; Water exchange; Workshops (Educational programs); Black Sea; Eurasia
• ISSN: 1816-3459; 1816-8957; 1816-3459
• DOI: 10.5194/sd-31-93-2022

The MagellanPlus workshop “BlackGate” addressed fundamental questions
concerning the dynamic evolution of the Mediterranean–Black Sea (MBS)
gateway and its palaeoenvironmental consequences. This gateway drives the
Miocene–Quaternary circulation patterns in the Black Sea and governs its
present status as the world's largest example of marine anoxia. The exchange
history of the MBS gateway is poorly constrained because continuous
Pliocene–Quaternary deposits are not exposed on land adjacent to the Black
Sea or northern Aegean. Gateway exchange is controlled by climatic
(glacio-eustatic-driven sea-level fluctuations) and tectonic processes in
the catchment as well as tectonic propagation of the North Anatolian Fault
Zone (NAFZ) in the gateway area itself. Changes in connectivity trigger
dramatic palaeoenvironmental and biotic turnovers in both the Black Sea and
Mediterranean domains. Drilling a Messinian to Holocene transect across the
MBS gateway will recover high-amplitude records of continent-scale
hydrological changes during glacial–interglacial cycles and allow us to
reconstruct marine and freshwater fluxes, biological turnover events, deep
biospheric processes, subsurface gradients in primary sedimentary
properties, patterns and processes controlling anoxia, chemical
perturbations and carbon cycling, growth and propagation of the NAFZ, the
timing of land bridges for Africa and/or Asia–Europe mammal migration, and the
presence or absence of water exchange during the Messinian salinity crisis.
During thorough discussions at the workshop, three key sites were selected
for potential drilling using a mission-specific platform (MSP): one on the
Turkish margin of the Black Sea (Arkhangelsky Ridge, 400 m b.s.f., metres below the seafloor), one on the
southern margin of the Sea of Marmara (North İmrali Basin, 750 m b.s.f.), and one
in the Aegean (North Aegean Trough, 650 m b.s.f.). All sites target Quaternary
oxic–anoxic marl–sapropel cycles. Plans include recovery of Pliocene
lacustrine sediments and mixed marine–brackish Miocene sediments from the
Black Sea and the Aegean. MSP drilling is required because the JOIDES Resolution
cannot pass under the Bosporus bridges. The wider goals are in line with the
aims and scope of the International Ocean Discovery Program (IODP) “2050 Science Framework: Exploring Earth by
Scientific Ocean Drilling” and relate specifically to the strategic
objectives “Earth's climate system”, “Tipping points in Earth's history”, and
“Natural hazards impacting society”.