In the composite section of San Miguel de Salinas the following synthems are represented: MI (preevaporitic
Messinan), MII (syn-evaporitic Messinian) and P (post-evaporitic Pliocene). The foraminiferal
assemblages of these synthems have been studied in order to reveal the palaeoenvironmental changes
related to the Mediterranean Salinity Crisis. The change between MI and MII synthems is characterized by
the reduction of the foraminiferal biodiversity. Synthem MII records palaeoenvironmental stress related to
the evaporitic deposition during the Salinity Crisis. Synthem P marks an abrupt increase of the foraminiferal
biodiversity in coincidence with the Pliocene reflooding of the Mediterranean Sea