The Westfalium (also Westphalian, rarely also wrongly Westphalium or Westphal) is a time period of the Carboniferous in the history of the earth . It is the middle regional level (or sub-series ) of the regional subsystem of Silesium in Central and Western Europe. The Westfalium corresponds to the global levels of the Upper Bashkirium and the Moskovium . In absolute terms, the Westphalian lasted from about 316.5 million to about 305 million years ago. The Westfalium is preceded by the Namurium , it is followed by the Stefanium , the highest regional level of the Silesium.
History and naming
Name and level were introduced into literature by Albert de Lapparent and Ernest Munier-Chalmas in 1892. The name is derived from the Westphalia region .
Definition and correlation
The beginning is defined by the first onset of the ammonite species Gastrioceras subcrenatum (Schlotheim). The Westfalium begins accordingly in the middle of the global level Bashkirium . The upper limit in Central Europe was originally a layer gap between Westfalium and Stefanium, the extent of which is very different. The upper limit has now been equated with the Moskovium / Kasimovium limit. However, the border between Westfalium and Stefanium is very controversial, since the Cantabrium , which was pushed between Westfalium and Stefanium and was added to the Stefanium, can so far only be reliably proven in Cantabria .
Corresponding to the uncertain upper limit and the different absolute time scales, the Westphalian reaches from 316.5 to 305 million years, or from about 315 to about 307 million years, or according to a calibration of the Pennsylvania by Menning et al. (2006) from 316.5 to 306 million years.
In Germany the Westfalium was traditionally divided into four sub-levels, which were designated with the letters A, B, C and D. In Belgium and England, Westfalium A – C were given their own names:
- ↑ a b c according to the Stratigraphic Table of Germany. These ages differ slightly from the ages in the International Stratigraphic Chart from 2009
- ↑ International Stratigraphic Chart from 2009 PDF ( Memento of the original from March 2, 2012 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice.
- ↑ see Menning et al. (2005: p. 191)
- Manfred Menning, Dieter Weyer, Immo Wendt and Günther Drozdzewski: A numerical time scale for the Pennsylvania in Central Europe. Courier Research Institute Senckenberg, 254: 181–198, Frankfurt / M., ISBN 3-510-61380-5
- Hans Murawski & Wilhelm Meyer: Geological dictionary . 10., rework. u. exp. Ed., 278 pages, Enke Verlag, Stuttgart 1998, ISBN 3-432-84100-0 .
- German Stratigraphic Commission, Manfred Menning (Hrsg.): Stratigraphische Tisch von Deutschland 2002 . Potsdam 2002, ISBN 3-00-010197-7 (1 sheet, Stratigraphie.de [PDF; 6.6 MB ]).
- Commission for the paleontological and stratigraphic research of Austria of the Austrian Academy of Sciences (Ed.): The Stratigraphic Table of Austria (sedimentary layer sequences). Vienna 2004 (PDF; 376 KB)