Oberostalpin
As Upper Austroalpine in the are geology those parts of the Austroalpine ceiling system designated by horizontal thrusts in the development of Alpine came to rest as the highest. Their tectonic movements - mainly thrusts - took place mainly in the Upper Cretaceous .
Smaller post-movements in the tertiary modified the tectonic picture at its edges - i.e. H. in the area of the (especially northern) Limestone Alps and the Grauwackenzone .
Large folds are unknown in the Eastern Alps, because the Eastern Alpine blanket systems were not created by overfolding, but by shearing their base ( shear blankets ).
The region of origin of the Upper Eastern Alpine and its carrier blanket of the Central Eastern Alpine Crystalline lies far to the south; the estimates range from about 100 to 200 km. Both units are part of the crustal plate advancing from the south , which led to the large-scale subduction of the then ( Penninic ) ocean floor and the formation of the Alps.
The Oberostalpin mainly includes
- the area of the Central Alps (mainly the so-called old crystalline on rocks ),
- the upstream areas of the Upper Eastern Alpine sediments: Northern Limestone Alps , Drauzug and Karawanken ,
- the Upper Eastern Alpine Paleozoic: northern Grauwackenzone , Landeck quartz phyllite , Murau and Graz Paleozoic
The Upper Eastern Alpine nappes are primarily characterized by a fully developed Mesozoic Era, while the Lower Eastern Alpine (e.g. eastern Switzerland, western Lower Tauern) has thin Triassic and coarse-clastic Jurassic layers.
The term Oberostalpins goes back to Tollmann . The newer structural geology also uses Central Eastern Alps , whereby the Lower Central Eastern Alps ( Middle Eastern Alps according to Tollmann) mainly comprises the old crystalline of the Central Alps, as well as the Tirolean of the Limestone Alps. The Oberostalpin after Tollmann is referred to together with the Bajuwarikum as the Oberes Zentralostalpin . This is because the Limestone Alps form a common tectonic layer with the Middle Eastern Alps in the Tollman sense. This reorganization is currently under discussion.
See also
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- Geological dictionary , Ferdinand Enke-Verlag, Stuttgart
- Geology in brief , Verlag Ferdinand Hirt, Kiel
- Geological structure of Austria , Springer-Verlag, p. 73 ff and 379 ff
- ↑ Nikolaus Froitzheim: Geology of the Alps Part 1: General and Eastern Alps. Lecture script , in: Rheinische Friedrich-Wilhelms-Universität Bonn: Structural Geology (online, uni-bonn.de, accessed August 10, 2016).
- ↑ FK Bauer, R. Oberhauser: The geological structure of Austria. Springer-Verlag, 2013, ISBN 9783709137444 , 2.4.3. The Grauwackenzone and its equivalents in the central Alps in connection with overlying remains from the Mesozoic and Eocene. P. 80 ff ( limited preview in Google Book search).