Mississippian

The Mississippian ( formerly Lower Carboniferous ) is in the earth's chronostratigraphisches a subsystem of the Carboniferous. It started before geochronological about 358.9 million years ago and ended about 323.2 million years. It follows the Devonian - series and is superimposed on Pennsylvanian subsystem of the carbon.

Naming and history

The name Mississippian was proposed by American geologist Alexander Winchell in 1869 and named after the Mississippi. It includes layers of limestone in America, 1891, the Mississippian of HS Williams was compared to the coal-rich layers of the Pennsylvaniums. However, this classification is not identical to the previous subdivision of the carbon in Europe. In 2004 it was from the International Commission on Stratigraphy (ICS ) and the International Union of Geological Sciences ( IUGS ​​) ratified as a subsystem of the Carboniferous.

Definition and GSSP

The beginning of the Mississippian ( and carbon ) is defined by the first appearance of the conodont species Siphonodella sulcata within the line of development of Siphonodella praesulcata to Siphonodella sulcata. The series ends at the time of Erstauftretens the conodont species Declinognathodus nodiliferus. The GSSP ( official reference profile of the International Commission on Stratigraphy ) of the Mississippian (and the Tournaisian and the carbon ) is the La Serre profile in the southeastern Montagne Noire ( France). It is an approximately 80 cm deep blight on the southern slope of the mountain La Serre, about 125 meters south of the summit (252 m ), approximately 525 m east of the Maison La Roquette, 2.5 km northeast of the town Fontès (Dept. Hérault, cabrières ).

Subdivision

Originally, the Mississippian in America was divided into regional Waverley and Tennessee stages. In adaptation to the international stage structure, it is now divided into three series ( lower, middle and Obermississippium ), each containing only one stage.

  • System: Carboniferous ( 358.9 to 298.9 mya ) Subsystem: Pennsylvanian (formerly Upper Carboniferous ) ( 323.2 to 298.9 mya )
  • Subsystem: Mississippian ( early Carboniferous ) ( 358.9 to 323.2 mya ) Series: Obermississippium ( 330.9 to 323.2 mya ) Level: Serpukhovian ( 330.9 to 323.2 mya )
  • Level: Viseum ( 346.7 to 330.9 mya )
  • Level: Tournaisium ( 358.9 to 346.7 mya )

Regional breakdown

The carbon was in Europe earlier in the Dinantium ( " Lower Carboniferous " ) and Silesium ( " Upper Carboniferous " ) divided. The former demarcation Lower Carboniferous / Upper Carboniferous in Europe does not match today's international boundaries. The upper limit of the Silesium does not match the current international carbon - Permian boundary.

Paleogeography

Baltica (mainly Europe) and Laurentia (mainly North America ) were merged into a single continent Laurussia. During the Mississippian of the southern continent Gondwana drifted toward Laurussia and collided in the Pennsylvanian with Laurussia.

Mya (unit) Cisuralian Asselian Gzhelian Kasimovian Moscovian (Carboniferous) Bashkirian Famennian History of the Earth Dinantian Silesian (series)
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