Paleobiological evidence of depositional conditions in the Salt Member, Gessoso-Solfifera Formation (Messinian, Upper Miocene) of Sicily

The micropaleontology of clayey layers within halite and kainite bodies in the Salt Member of the Lower Evaporitic Complex, in the Messinian (uppermos t Miocene) Gessoso-Solfifera Formation, has been studied in samples taken f rom Racalmuto and Realmonte salt mines on the southern coast of Sicily. Ric h paleobiological associations have been observed of (on the whole) well pr eserved foraminifers, nannoplankton, dinoflagellate cysts and pollen grains . The integrated analyses point to several normal-marine influxes that inte rrupted the formation of the evaporite deposits. The greatest influx of mar ine water (in probable correspondence with high relative sea level) occurre d during the deposition of the earliest Unit C. Based on these data, a time -scale of the Salt Member deposition may be proposed for the first time, pl acing the salt deposition between isotope stages TG20 and TG22, in the inte rval 5.72 to 5.75 Ma. The micropaleontology indicates that salt deposition took place under warm and dry conditions characteristic of tropical to subt ropical climates, and that there was no significant climatic change associa ted with the Salinity Crisis.