Messinian


The Messinian is in the geologic timescale the last age or uppermost stage of the Miocene. It spans the time between 7.246 ± 0.005 Ma and 5.333 ± 0.005 Ma. It follows the Tortonian and is followed by the Zanclean, the first age of the Pliocene.
The Messinian overlaps the Turolian European Land Mammal Mega Zone and the Pontian Central European Paratethys stage. It also overlaps the late Huayquerian and early Montehermosan South American Land Mammal Ages, and falls inside the more extensive Hemphillian North American Land Mammal Age.
During the Messinian, around 6 million years ago, the Messinian salinity crisis took place, which brought about repeated desiccations of the Mediterranean Sea.

Definition

The Messinian was introduced by Swiss stratigrapher Karl Mayer-Eymar in 1867. Its name comes from the Italian city of Messina on Sicily, where the Messinian evaporite deposit is of the same age.
The base of the Messinian is at the first appearance of the planktonic foram species Globorotalia conomiozea and is stratigraphically in the middle of magnetic chronozone C3Br.1r. The Global Boundary Stratotype Section and Point for the Messinian is located in a section at Oued Akrech, near the Moroccan capital Rabat.
The top of the Messinian lies with the top of magnetic chronozone Cr3. The top is also close to the extinction level of the calcareous nanoplankton species Triquetrorhabdulus rugosus and the first appearance of nanoplankton Ceratolithus acutus.