Neunkirchen formation
In the history of the earth, the Neunkirchen Formation is a lithostratigraphic rock unit in the Upper Carboniferous of the Saar-Nahe basin . It follows the Spiesen formation and is overlaid by the St. Ingbert formation . The lower part is dated in the Westfalium A, the upper part in the Westfalium B ( Upper Carboniferous or Pennsylvanian ).
Naming and conceptual history
The Neunkirchen formation does not come to light in the Saar-Nahe basin, but was only drilled (research well Saar 1). This was sunk in the district of Neunkirchen on the southern outskirts of Neunkirchen ( Saarland ), hence the name. The term was introduced in 1976 by Hans Wilhelm Weingardt as "Neunkirchen layers" and later changed to "Neunkirchen formation" in line with the terminology of lithostratigraphy.
Definition, age and storage space
The lying boundary is the beginning of the coal-bearing Upper Carboniferous in the Saar-Nahe Basin, the upper boundary the lower edge of the base conglomerate of the St. Ingbert Formation. In the Saar 1 research well, it is 462 m thick. It consists of coarse to fine sand stones. Overall, the formation shows a "fining-upward" trend; H. the grain size tends to increase towards the top of the formation. Several sequences can also be observed within the formation, each of which is coarser at the base and finer towards the top (“fining upward” cycles). Overall, coal seams 151 to 106 (of the 151 coal seams penetrated by the Saar 1 borehole) belong to the Neunkirchen formation. According to the flora content found, the lower part belongs to the Westfalium A, the upper part to the Westfalium B. This led to a subdivision into a lower and an upper Neunkirchen formation. After this sequence of sandstones, the deposition in an anastomosing river is most likely. After the STD2005 the entire formation belongs to the Westfalium A ( Langsettium ).
Structure and position
Weingardt (1976) subdivided the Neunkirchen formation into a lower Neunkirchen formation and an upper Neunkirchen formation, which are understood as sub-formation in the hierarchical level of the lithostratigraphic units. However, they cannot be justified sedimentologically or lithostratigraphically, so Schäfer (2005) rejects them. The Neunkirchen formation is the lowest formation in the Saarbrücken group and the only formation in the Lower Saarbrücken subgroup.
swell
literature
- Andreas Schäfer: Sedimentologically-numerically based stratigraphic standard for the permo-carbon of the Saar-Nahe basin. Courier Forschungsinstitut Senckenberg (Stratigraphie von Deutschland V - Das Oberkarbon (Pennsylvanium) in Germany), 254: 369–394, Frankfurt 2005 ISBN 3-510-61380-5
Individual evidence
- ↑ Stratigraphic table from Germany 2002
Web links
- German Stratigraphic Commission (Ed.): Stratigraphische Tisch von Deutschland 2002 . Potsdam 2002 ISBN 3-00-010197-7 - PDF (6.7 MB) (abbreviated STD2002)