Latest Miocene benthic delta super(18)O changes, global ice volume, sea level and the "Messinian salinity crisis"

Oxygen isotope evidence indicates high but variable delta super(18)O values in benthic foraminiferal calcite during the latest Miocene and earliest Pliocene. These high values may represent increases in global ice volume and associated sea-level fall. The delta super(18)O record resembles glacial/interglacial cycles, but with only one-third the amplitude of the late Pleistocene signal. This variability may reflect instability in the Antarctic ice sheet, and palaeomagnetic correlation points to an isotopic event coinciding with the isolation and desiccation of the Mediterranean basin during the latest Messinian.