The Pennsylvanian ( formerly Upper Carboniferous ) is in the earth's chronostratigraphisches a subsystem of the Carboniferous. It started before geochronological about 323.2 million years ago and ended about 298.9 million years. It follows the Mississippian subsystem of the Carboniferous and is detached from the Cisuralium series of the Permian.
Naming and history
The Pennsylvanian is named after the U.S. state of Pennsylvania. 1891 HS Williams presented the calcareous strata of the Mississippian the coal-rich strata of the Pennsylvanian opposite. In 2004 it was as a subsystem of the carbon by the International Commission on Stratigraphy (ICS ) and the International Union of Geological Sciences ( IUGS ) ratified.
Definition and GSSP
The lower limit of the series and the Bashkirian stage is characterized by the first appearance of the conodont species Declinognathodus nodiliferus sl defined. The upper limit is the first appearance of the conodont species Streptognathodus isolatus. The official reference profile of the International Commission on Stratigraphy ("Global Stratotype Section and Point" = GSSP ) for the Pennsylvanian and the Bashkirian is a profile in the Battleship Wash Formation in the Arrow Canyon ( Nevada, USA).
The Pennsylvanian is now divided into three international series ( lower, middle and Oberpennsylvanium ) and in four international chronostratigraphic stages:
- System: Carboniferous ( 358.9 to 298.9 mya ) Subsystem: Pennsylvanian (formerly Upper Carboniferous ) ( 323.2 to 298.9 mya ) Series: Oberpennsylvanium ( 307 to 298.9 mya ) Level: Gzhelium ( 303.7 to 298.9 mya )
- Level: Kasimovian ( 307 to 303.7 mya )
- Level: Moscovian ( 315.2 to 307 mya )
- Level: Bashkirian ( 323.2 to 315.2 mya )
In Europe, the carbon in Dinantium ( " Lower Carboniferous " ) and Silesium was divided ( " Upper Carboniferous "); However, the boundary does not coincide with the Unter-/Oberkarbon international Mississippium-/Pennsylvanium-Grenze. Also the Silesium ends before the international carbon - Permian boundary. The Silesium was divided into the stages Namurium, Westfalium and Stefanium.
The Pennsylvanian is characterized by the collision of the southern continent Gondwana with the northern continent Laurussia mentioned. It was a along the collision zone an extended fold-mountain belt which is called Herzynisches system and its geological remains today among other things in the form of the Appalachians in North America and the Variscan massifs (eg Massif Central, Rhenish Slate Mountains, Bohemian Massif ) exist in Europe. This collision was one of the last phases of the formation of the supercontinent Pangaea, which was completed with the annexation Sibirias in Perm.
The lowering of the Hercynian foreland system took on large amounts of sediments. As they stretched approximately along the equator, flourished there through the warm, moist air lush forests, thereby accumulated together with the sediments much biomass. This biomass was converted in the course of Earth's history to coal deposits, which formed the basis for the industrial revolution in Europe and North America in the late 19th century.