Pennsylvania

system	Subsystem	step	≈ age ( mya )
higher	higher	higher	younger
Carbon	Pennsylvania	Gzhelium	298.9 ⬍ 303.7
		Kasimovium	303.7 ⬍ 307
		Moskovium	307 ⬍ 315.2
		Bashkirium	315.2 ⬍ 323.2
	Mississippium	Serpukhovium	323.2 ⬍ 330.9
		Visa	330.9 ⬍ 346.7
		Tournaisium	346.7 ⬍ 358.9
deeper	deeper	deeper	older

The Pennsylvania (formerly Upper Carboniferous ) is a chronostratigraphic subsystem of the Carboniferous in the history of the earth . It began geochronologically about 323.2 million years ago and ended about 298.9 million years ago. It follows the Mississippian subsystem of the Carboniferous and is replaced by the Cisuralium series of the Permian .

Naming and history

Pennsylvania is named after the US state of Pennsylvania . In 1891, HS Williams contrasted the calcareous strata of the Mississippium with the coal-rich strata of Pennsylvania. In 2004 it was ratified as a subsystem of carbon by the International Commission on Stratigraphy (ICS) and the International Union of Geological Sciences (IUGS).

Definition and GSSP

The lower limit of the series and the Bashkirian stage is due to the first appearance of the conodont species Declinognathodus nodiliferus s. l. Are defined. The upper limit is the first appearance of the conodont species Streptognathodus isolatus . The official reference profile of the International Commission for Stratigraphy ("Global Stratotype Section and Point", GSSP) for the Pennsylvania and the Bashkirium is a profile in the Battleship Wash Formation in Arrow Canyon ( Nevada , USA).

Breakdown

The Pennsylvania is today divided into three international series (lower, middle and upper Penny sylvanium) and four international chronostratigraphic levels :

System : carbon (358.9–298.9 mya )
- Subsystem : Pennsylvania (formerly Upper Carboniferous) (323.2–298.9 mya)
  - Series : Oberpennsylvanium (307–298.9 mya)
    - Level : Gzhelium (303.7–298.9 mya)
    - Level: Kasimovium (307-303.7 mya)
  - Series: Mittelpennsylvanium (315.2–307 mya)
    - Level: Moskovium (315.2–307 mya)
  - Series: Unterpennsylvanium (323.2–315.2 mya)
    - Level: Bashkirium (323.2-315.2 mya)
- Subsystem: Mississippium (formerly Lower Carboniferous) (358.9–323.2 mya)

Regional breakdown

In Europe, carbon was divided into dinantium ("lower carbon") and silesium ("upper carbon"); however, the Lower / Upper Carboniferous boundary does not coincide with the international Mississippian / Pennsylvania boundary. Silesium also ends before the international Carbon-Permian border. The Silesium was divided into the stages Namurium , Westfalium and Stefanium .

geology

The Pennsylvania is characterized by the collision of the southern continent Gondwana with the northern continent called Laurussia . This created an extensive fold mountain belt along the collision zone, which is called the Herzynisches System and whose geological remains are still u. a. exist in the form of the Appalachian Mountains in North America and the Variscan Massif (e.g. Massif Central , Rhenish Slate Mountains , Bohemian Massif ) in Europe. This collision was one of the last phases of the formation of the supercontinent Pangea , which was completed with the annexation of Siberia in the Permian .

The foreland depressions of the Hercynian System received large amounts of sediment. Since they stretched roughly along the equator, lush forests thrived there due to the warm and humid climate, which together with the sediments accumulated a lot of biomass. In the further course of the earth's history, this biomass was converted into the hard coal deposits, which formed the basis for the industrial revolution in Europe and North America in the late 19th century.

literature

Felix Gradstein, Jim Ogg, Jim & Alan Smith: A Geologic timescale. Cambridge University Press 2004, ISBN 0-521-78673-8
H. Richard Lane, Paul L. Brenckle, JF Baesemann, and Barry Richards: The IUGS boundary in the middle of the Carboniferous: Arrow Canyon, Nevada, USA. In: Episodes. 22 (4): 272-283, Beijing 1999.