Zechstein
Zechstein is a lithostratigraphic group of the Dyas in northern Central Europe. The Dyas (which is divided into two, after the division into Rotliegend and Zechstein) was the name coined in Central Europe for the Permian , which however could not prevail internationally. In the past, the term Zechstein (like the Rotliegend) was also viewed as a unit of time and correlated with the Upper Permian. This is no longer practiced today, because the lying border to the Rotliegend is diachronous and therefore unsuitable as a time stamp. The Zechstein / Buntsandstein hanging end border is also in front of the international Perm-Triassic border . The Zechstein is therefore only interpreted in literature today as a rock unit (= unit of lithostratigraphy ), no longer as a time interval in the history of the earth. The center of the Zechstein Basin was in northern and central Germany and in Poland . The Zechstein follows the rock unit of the Rotliegend and is overlaid by the lithostratigraphic group of the Buntsandstein.
History and naming
On the one hand, Zechstein is a mining term that means "tough stone". On the other hand, this word is reminiscent of the "Zechstein", on which the collieries (mining buildings) for the extraction of copper slate were.
definition
The Zechstein in the lithostratigraphic sense begins with the deposition of the copper slate. The Zechstein Sea , coming from the north, left behind up to seven cycles of erosive-sedimentary / marine- Euxinian sediments (Werra, Staßfurt, Leine, Aller, Ohre, Friesland and Fulda) in its large-scale forays into today's Central European regions . An eighth cycle is occasionally discussed in the literature, but it has not yet been proven with certainty. Due to regional variance in the morphology of the basement and due to a change in this paleogeography in the course of the Upper Permian, nowhere in the Zechstein basin are all cycles fully developed.
The Zechstein is today mainly with the international chronostratigraphic stages of wuchiapingian and changhsingian correlated to the series of Lopingium be combined (or Permian). The Zechstein ends shortly before the Permian Triassic border in the upper Changhsingium. The Zechstein base is diachronous , and therefore the Rotliegend sedimentation could extend into the Wuchiapingium. In absolute terms, expressed the Zechstein began about 257.3 million years ago and ended about 251 million years ago.
Breakdown
The Zechstein Group is divided into seven formations in the basin center in Northern Germany, which correspond to the seven cycles (in stratigraphic sequence):
- Fulda formation (zFu)
- Friesland Formation (zFr)
- Ear formation (zO)
- Aller formation (zA)
- Leash formation (zL)
- Staßfurt formation (zS)
- Werra formation (zW)
At the edge of the pool on the eastern edge of the Rhenish Slate Mountains:
- Frankenberg formation (zFb)
- Geismar formation (zGs)
- Ststätteberg Formation (zSb)
- Battenberg Formation (rzBt)
In the northern Palatinate, also on the edge of the basin, is deposited:
- Stauf formation (zSt)
In the Upper Palatinate:
- Lindau formation (zLi)
At the edge of the basin in Baden-Württemberg, the Zechstein Group is divided into four formations:
- Tiger sandstone formation (partly)
- Langenthal Formation (zLa)
- Zechsteindolomit-Formation (zD)
- Kirnbach Formation (zK)
The Kirnbach formation interlocks with the Zechsteindolomit formation and the tiger sandstone formation, the latter also interlocks with the Langenthal formation.
Economical meaning
The Kupferschiefer had due to its regional reinforced occurring ferrous metal guide until the end of the twentieth century great as silver and copper supplier from the Middle Ages economic importance.
The second important natural resource that was formed in the Zechstein era is the rock and potash salts , which are still heavily extracted today .
As a third important mineral resource, the mighty anhydrite deposits or the gypsum that emerged from them through water absorption have been used intensively for centuries. Especially in the southern Harz Zechstein belt , gypsum opencast mines characterize the landscape in many places. This leads to fierce controversy between the associations of the gypsum industry and nature conservation efforts.
literature
- Manfred Menning, Reinhard Gast, Hans Hagdorn, Karl-Christian Käding, Theo Simon, Michael Szurlies, Edgar Nitsch: Time scale for Permian and Triassic in the Stratigraphic Table of Germany 2002, cyclostratigraphic calibration of the higher Dyas and Germanic Trias and the age of the Roadium stages to Rhaetium 2005. Newsletters on Stratigraphy, 41 (1-3): pp. 173-210, Stuttgart 2005 ISSN 0078-0421
- Edgar Nitsch, Hubert Zedler: Upper Carboniferous and Permian in Baden-Württemberg. State Office for Geology, Raw Materials and Mining, Information, 22: pp. 7–102, Freiburg 2009.
Web links
- Proposal 69: Zechstein Formations (PDF; 21 kB) Subcommission for Permian Triassic Stratigraphy in the German Stratigraphic Commission (DSK)
- Zechstein . Mineral atlas
Individual evidence
- ↑ See point “Age classification” in H. Lützner: Neuenhof-Formation. In: LithoLex [online database]. BGR, Hanover, data record no .: 22, last updated on January 10, 2007; Retrieved December 3, 2015
- ↑ Heinrich Bahlburg, Christoph Breitkreuz: Fundamentals of geology . 2nd Edition. Spektrum Akademischer Verlag, Munich 2004, p. 129
- ↑ Mandy Henning: Voluntary cooperation between nature conservation and the gypsum industry using the example of the district of Osterode am Harz. (PDF; 3.21 MB) Dipl.-Arb., Univ. Lüneburg, Department of Environmental Sciences, 2006, p. 31 ff.
- ↑ The Harz Gypsum Company Working Group
- ^ Friends of Nature Lower Saxony: Gypsum karst in the southern Harz