Impact of the Mediterranean-Atlantic connectivity and the late Miocene carbon shift on deep-sea communities in the Western Alboran Basin

Integration of foraminiferal and geochemical data (stable isotope elemental composition) from West Alboran Basin (WAB) ODP Site 976 allowed evaluation the effects initial Mediterranean – Atlantic restriction event preceding Messinian Salinity Crisis (MSC) in a context late Miocene cooling diminishing water mass exchange close to Gibraltar Strait. At 7.17 Ma prominent shift benthic foraminifer abundances dominantly oxic taxa species tolerating oxygen deficiency, paired with drop ?13C values, suggest that Mediterranean-Atlantic gateways profoundly affected WAB deep waters. From onward, deep-water stagnation increased bottom residence time led depletion. Similar changes, already identified other basins imply first signs significantly predated onset MSC also WAB, an area sometimes considered more under influence Atlantic. Simultaneously, marked amplitude increase several element-log ratios reveals clear cyclical pattern related precession. Together new ?18O data, identification patterns improving age model consequently enabled accurate correlation Mediterranean, mostly land-based sections. Comparing records, we were able correlate at basinal scale refine thermohaline circulation models after Ma. Because this Mediterranean-scale change was contemporaneous global Late Carbon Isotope Shift (LMCIS) it important discern between local effects. Given synchronicity record, effect certainly Basin. However, opposite phase relations signals orbital parameters, higher magnitude our record suggests imprint overruled one.