Latest Miocene restriction of the Mediterranean Outflow Water: a perspective from the Gulf of Cádiz

• Published in: Geo-Marine Letters
• Main Authors: Ng, Zhi Lin, Hernández-Molina, F. Javier, Duarte, Débora, Sierro, Francisco J., Ledesma, Santiago, Rogerson, Michael, Llave, Estefanía, Roque, Cristina, Manar, M. Amine
• Other Authors: Royal Holloway, University of London, SCORE Project, INPULSE Project
• Format: Article in Journal/Newspaper
• Language: English
• Published: Springer Science and Business Media LLC 2021
• Subjects: Earth and Planetary Sciences (miscellaneous); Geotechnical Engineering and Engineering Geology; Environmental Science (miscellaneous); Oceanography; North Atlantic
• Online Access: http://dx.doi.org/10.1007/s00367-021-00693-9; https://link.springer.com/content/pdf/10.1007/s00367-021-00693-9.pdf; https://link.springer.com/article/10.1007/s00367-021-00693-9/fulltext.html

Abstract The Mediterranean-Atlantic water mass exchange provides the ideal setting for deciphering the role of gateway evolution in ocean circulation. However, the dynamics of Mediterranean Outflow Water (MOW) during the closure of the Late Miocene Mediterranean-Atlantic gateways are poorly understood. Here, we define the sedimentary evolution of Neogene basins from the Gulf of Cádiz to the West Iberian margin to investigate MOW circulation during the latest Miocene. Seismic interpretation highlights a middle to upper Messinian seismic unit of transparent facies, whose base predates the onset of the Messinian salinity crisis (MSC). Its facies and distribution imply a predominantly hemipelagic environment along the Atlantic margins, suggesting an absence or intermittence of MOW preceding evaporite precipitation in the Mediterranean, simultaneous to progressive gateway restriction. The removal of MOW from the Mediterranean-Atlantic water mass exchange reorganized the Atlantic water masses and is correlated to a severe weakening of the Atlantic Meridional Overturning Circulation (AMOC) and a period of further cooling in the North Atlantic during the latest Miocene.