The Messinian (also shortened to Messin ) is in Earth's history the top chronostratigraphic stage of the Miocene ( Neogene ). It corresponds approximately to the period prior geochronological 7.246 to about 5.333 million years ago and lasted about 1.9 million years. The stage following the Tortonian and the Zancleum, the lower stage of the Pliocene, detached.
Naming and history
The stage is named after the city of Messina in Sicily (Italy). The stage and the name was introduced by the Swiss geologist Karl Mayer- Eymar 1867.
Definition and GSSP
The lower limit is defined by the lowest occurrence of planktonic foraminifera species Globorotalia conomiozea. The limit is approximately in the center of the magnetic polarity chronozone C3Br.1r. The upper limit is at the top of the magnetic polarity chronozone C3R ( about 100,000 years before the Thvera normal - polar Subchronozone C3n.4n ). In addition, the boundary is close to the calcareous nannoplankton Aussterbehorizont the -art Triquetrorhabdulus rugosus ( = base of CN10b zone) and the first appearance of calcareous nannoplankton - type Ceratolithus acutus. The official type profile of the International Commission on Stratigraphy ( GSSP = " Global Stratotype Section and Point" ) is a profile at Oued Akrech near Rabat ( Morocco).
Messinian Salinity Crisis in the Mediterranean
During the Messinian the Mediterranean largely dried up and were formed in the deepest parts of Beck to mighty to 3000 m evaporite sequences.
See Messinian Salinity Crisis Article