Silesium

The Silesium (also shortened to Siles ) (or incorrect Siles stage) is in the Earth's upper regional and supra-regional subsystem (or series earlier stage) of the Carboniferous in Central and Western Europe and the equivalent of the European Upper Carboniferous. It follows the regional or supra-regional subsystem of Dinantium and is overlaid by the Permian system. The lower limit lies within the global subsystem of the Pennsylvania , the upper limit is also not identical to the lower limit of the Permian system, but ends earlier in the Gzhelium stage, i.e. that is, it cannot be equated with Pennsylvania. Expressed in absolute terms, Silesium ranges from around 345.3 million years ago to 299 million years ago.

Fossils of the Westfal D des Silesium ( Oberkarbon or Pennsylvanium ) from the Cainsdorf strike of the Zwickau coal field . Left: Sigillariaceae remains (extinct club moss plants ), in the lower center Annularia sphenophylloides leaves of the Calamitaceae ( horsetail ), right the Linopteris neuropteroides leaves of the extinct Medullosales ( seed ferns ). Date of origin: approx. 305-310 million years ago

History and naming

It is named after the neo-Latin expression Silesia for Silesia , where coal deposits from this geological period were found. The other important hard coal deposits in Europe also originated in the Upper Carboniferous. The term was introduced in 1958 by the 4th Congrès pour l 'advancement des études de stratigraphie carbonifère in Heerlen (Netherlands) on the recommendation of the sub-commission for carbon sratigraphy. The Silesium received the rank of a subsystem. However, the Silesium could not establish itself in international use. In 2004, the ratified International Union of Geological Sciences , the Mississippian and Pennsylvanian as subsystems of carbon. Since then, the Silesium has only been used on a regional or supra-regional level. However, some authors advise against the further use of the term Silesium and Oberkarbon.

Definition and correlation

The lower limit of the Silesium and the Namurium is defined by the onset of the ammonite species "Cravenoceras" leion (= Emstites leion ). The upper limit and thus the limit to the regional level of the Autunium is extremely problematic, since this time range in Central Europe does not contain any marine fossils. At least in the lithostratigraphic sense, the Central European Upper Carboniferous ends well before the global Carbon / Permian boundary in the Gzhelian , since the Central European Rotliegend (with its basal regional level Autunium) still extends into the Global Carboniferous. In the chronostratigraphic sense, it corresponds to the Pennsylvania (except for its highest parts) and the highest part of the global Mississippian .

Breakdown

The Silesium is traditionally divided into regional levels (sometimes also referred to as series)

Stefanium
Westfalium (occasionally the spelling Westphalium can also be found)
Namurium

subdivided.

Alternatively, in England and Western Europe, there was a breakdown into the following regional levels:

The terms are rarely used in publications that deal with the stratigraphy of the Central European carbon.

The Silesium in Central Europe

During the Silesian period, large forests grew in the parali fringes of the Variscicum , which later became the coal seams of Central and Western Europe. The Variscan orogeny ended in the higher Silesian .

swell

Individual evidence

↑ Hans-Georg Herbig: The international Mississippium-Pennsylvanian border - development of the concept, definition and application in Germany. Courier Forschungsinstitut Senckenberg, 254: 3–12, Frankfurt / M. ISSN 0341-4116
↑ The adjective paralisch means “belonging to the coast” and in geology refers to areas close to the coast that were in phases flooded by the sea and were accordingly subject to alternating terrestrial and marine sedimentation conditions. Compare the lexicon entry "paralisch". www.mineralienatlas.de, accessed on August 20, 2013 .

literature

Hans-Georg Herbig: The international Mississippium-Pennsylvania border - development of the concept, definition and application in Germany. Courier Forschungsinstitut Senckenberg, 254: 3–12, Frankfurt / M. ISSN 0341-4116
Dieter Weyer and Manfred Menning: Geological time scale, stratigraphic nomenclature and magnetostratigraphy. In: German Stratigraphic Commission (Ed.): Stratigraphie von Deutschland VI Unterkarbon (Mississippium). Publication series of the German Society for Geosciences, 41: 27–50, Hannover 2006 ISBN 3-932537-37-8

Web links

[1] Hans-Georg Herbig: The international Mississippium-Pennsylvanian border - development of the concept, definition and application in Germany. Courier Forschungsinstitut Senckenberg, 254: 3–12, Frankfurt / M. ISSN 0341-4116

[2] The adjective paralisch means “belonging to the coast” and in geology refers to areas close to the coast that were in phases flooded by the sea and were accordingly subject to alternating terrestrial and marine sedimentation conditions. Compare the lexicon entry "paralisch". www.mineralienatlas.de, accessed on August 20, 2013 .