Hasel Mountains
The Haselgebirge is a mixed rock consisting of clay minerals , sandstone , anhydrite , rock salt and secondary salts. The rock salt content fluctuates between 10% and 70%, so that it has been mined in its occurrence areas for a long time. The best-known deposits are in the Northern Limestone Alps , others are salt-clay mixtures linked to the rise of salt domes in Northern Germany .
term
"Haselgebirge" is an old expression that was used by miners for a mixture of rock salt , gypsum and clay cemented into a breccia . The name, originally only referring to this rock-like material, was expanded in the course of geological research to include all such rock deposits and their adjacent rock, for example in the Eastern Alps. In the Eastern Alps, it no longer describes a single rock, but a sedimentary and tectonic facies .
Formation of the Eastern Alpine Hasel Mountains
The formation took place in the Upper Permian to Scythian in shallow lagoons and sedimentary basins without drainage , which formed in tectonic trenches in the eastern Alpine sedimentation area. Brief influx of salty seawater from the Tethys and subsequent evaporation of the water led to the formation of evaporites in the central trench area, which were lined with sabchas , sandy salt clay plains and rubble fans from the adjacent trench shoulders. This environment was hostile to life, so that fossils are missing apart from a few spores .
After their formation and covering by younger deposits, the sediments were subject to strong leaching and salt tectonics , which began to blur the originally sub-parallel stratification of the sediments . Due to the strong overprinting of the tectonic processes during the Alpidic orogeny and the unfolding of the Alps , most of the remaining stratification was also lost, reinforced by the proximity of the rocks to the base thrust of the Northern Limestone Alps and the low resistance of the salt to tectonic forces. The rocks involved are therefore rolled out, severely broken (brecciated) and contain, in addition to isolated areas of original stratification, fragments of dolomite and rauwacke. A plastic rubble, cemented by the rock salt, formed, a sandy, gray to greenish salt tone with inclusions of anhydrite, rock salt and dolomite.
Occurrence
Hasel Mountains form the bulk of the eastern Alpine salt deposits. In Altaussee , Bad Ischl , Hallstatt and Berchtesgaden , the salt mines are still in operation at the beginning of the 21st century. The plants in Hallein and Hall in Tirol are closed.
Some salt domes in the subsurface of northern northern Germany also have Hasel Mountains, but this was only created in the course of the ascent of the salt from great depths (2000–5000 m). The original rock consists of up to 15 layers of rock salt from the High Permian ( Oberrotliegend ), which alternate with red claystone and sandstone packets. These “Haselgebirg diapirs ”, which also contain salt from the highest Permian ( Zechstein ) and are therefore also referred to as “double salinaries”, are spatially limited to southern Schleswig-Holstein , the extended Lower Elbe region , western Mecklenburg , East Frisia and the German Bight .
Dismantling
The alpine salt deposits are leached with the help of water that is brought into artificially created cavities - leaching plants or surface boreholes . This process creates an aqueous salt solution, the brine , on the one hand, and the water-insoluble constituents of the Hasel Mountains , the Laist , sink to the bottom of the liquor on the other . By evaporating the water content of the brine - historically in the Pfannhaus , today in industrial evaporator systems - the table salt is finally obtained.
literature
- Alois Fellner: Miner's manual dictionary for technical terms in the salt mining and brewing industry. Vienna 1999
- Carl von Scheuchenstuel : Idioticon of the Austrian mountain and hut language. Vienna 1856
- Othmar Schauberger: Construction and formation of the salt deposits of the Eastern Alpine Salinar. Vienna 1986.
- ÖNORM G 1043: Terms of evaporite deposits. Vienna 1985
- Ch. Spötl: Sedimentological-facial analysis of tectonized evaporite series - a case study of the Alpine Hasel Mountains (Permoskyth, Northern Limestone Alps). Geological-Palaeontological Communications Innsbruck, Vol. 15., pp. 59–69, Innsbruck 1988 (PDF file; 1.15 MB)
- Georg W. Mandl: Short notes on the Hallstatt salt rock - the "Hasel Mountains". Reports of the Federal Geological Institute, Vol. 49, pp. 91–95, Vienna 1999
Individual evidence
- ^ Hans Murawski, Wilhelm Meyer: Geological dictionary . 11th edition. Elsevier / Spektrum, Heidelberg 2004, ISBN 3-8274-1445-8 , pp. 93 .
- ^ Walter Freudenberger and Klaus Schwerd: Geological map of Bavaria 1: 500000 with explanations. 1 card + explanations + 8 supplements . 4th edition. Bavarian Geological State Office, Munich 1996, p. 220 .
- ↑ Mandl 1999
- ↑ F. Kockel, P. Krull (project leader): Final storage of radioactive waste that generates high levels of heat in deep geological formations in Germany. Investigation and evaluation of salt formations. ( Memento of the original from December 10, 2014 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. BGR Hannover, 1995. p. 30 (pdf; 6.17 MB)
