Tyssaer Wände
Encyclopedia
The Tyssaer Wände are a well-known group of rocks in the western Bohemian Switzerland not far from its topographical boundary with the Ore Mountains
. The region, with its rock pillars up to 30 m high, is one of the major tourist attractions of Bohemian Switzerland. The Tyssaer Wände and their neighbouring Bürschlitzwände (Bürschlické stěny) are protected as a national nature reserve.
from the Ore Mountain escarpment on Czech soil. About a kilometre west of them on the outskirts of Tyssa stands the coarse- and medium-grained muscovite
-biotite
-orthogneiss
of the Eastern Ore Mountain region. This also strikes
eastwards on the hillside south of the village.
The rocks are frequently vertically dissected; in many places the fissures being as deep as the rock pillars are high. Horizontal weathering is found in the upper layers and have created several bizarre shapes, such as the rock called the Steinpilz ("boletus" - a type of toadstool) which is easily accessible.
The Große Tyssaer Steine ("Great Tyssa Rocks") begin near the official entrance by a restaurant. These consist of a northern and southern array of crags along an otherwise compact plateau. The crags to the west running off at an angle to the northwest are known as the Kleine Tyssaer Steine ("Little Tyssa Rocks"). They are more heavily dissected.
The crags of the Tyssaer Wände comprise mainly of medium-grained sandstone
of the Lower to Middle Turonian
of the Cretaceous
. They belong lithostratigraphically to the Weissenberg Formation (Bělohorské souvrství) in the Bohemian Cretaceous System. The nearby area surrounding the Tyssaer Wände to the north and south is covered by diluvial
sediments of loam
, sand
and boulder-containing scree
.
In the sandstone are heavy concentrations of ferrous minerals on closely spaced strata, that can be identified from their yellow to red stripes of colour and predominantly horizontal. A striking feature in many places where the lower strata are visible are small and large cavities as well as occasional tunnels with an oval cross-section, whose walls are often covered with calcareous sinter
deposits. These are relics of very old solution processes in the sandstone.
In zones of strong weathering
, the marked stratification over short distances is clearly visible. Features associated with cross-bedding
occur relatively frequently.
Ore Mountains
The Ore Mountains in Central Europe have formed a natural border between Saxony and Bohemia for many centuries. Today, the border between Germany and the Czech Republic runs just north of the main crest of the mountain range...
. The region, with its rock pillars up to 30 m high, is one of the major tourist attractions of Bohemian Switzerland. The Tyssaer Wände and their neighbouring Bürschlitzwände (Bürschlické stěny) are protected as a national nature reserve.
Topography and geology
The Tyssaer Wände are located at a height of about 600 m above sea level. They form a line of rock outcrops drawn up in an arc on the westernmost edge of the sandstone beds of the Elbe Sandstone MountainsElbe Sandstone Mountains
The Elbe Sandstone Mountains, also called the Elbe sandstone highlands is a mountain range straddling the border between the state of Saxony in southeastern Germany and the North Bohemian region of the Czech Republic, with about three-quarters of the area lying on the German side...
from the Ore Mountain escarpment on Czech soil. About a kilometre west of them on the outskirts of Tyssa stands the coarse- and medium-grained muscovite
Muscovite
Muscovite is a phyllosilicate mineral of aluminium and potassium with formula KAl22, or 236. It has a highly-perfect basal cleavage yielding remarkably-thin laminæ which are often highly elastic...
-biotite
Biotite
Biotite is a common phyllosilicate mineral within the mica group, with the approximate chemical formula . More generally, it refers to the dark mica series, primarily a solid-solution series between the iron-endmember annite, and the magnesium-endmember phlogopite; more aluminous endmembers...
-orthogneiss
Gneiss
Gneiss is a common and widely distributed type of rock formed by high-grade regional metamorphic processes from pre-existing formations that were originally either igneous or sedimentary rocks.-Etymology:...
of the Eastern Ore Mountain region. This also strikes
Strike and dip
Strike and dip refer to the orientation or attitude of a geologic feature. The strike line of a bed, fault, or other planar feature is a line representing the intersection of that feature with a horizontal plane. On a geologic map, this is represented with a short straight line segment oriented...
eastwards on the hillside south of the village.
The rocks are frequently vertically dissected; in many places the fissures being as deep as the rock pillars are high. Horizontal weathering is found in the upper layers and have created several bizarre shapes, such as the rock called the Steinpilz ("boletus" - a type of toadstool) which is easily accessible.
The Große Tyssaer Steine ("Great Tyssa Rocks") begin near the official entrance by a restaurant. These consist of a northern and southern array of crags along an otherwise compact plateau. The crags to the west running off at an angle to the northwest are known as the Kleine Tyssaer Steine ("Little Tyssa Rocks"). They are more heavily dissected.
The crags of the Tyssaer Wände comprise mainly of medium-grained sandstone
Sandstone
Sandstone is a sedimentary rock composed mainly of sand-sized minerals or rock grains.Most sandstone is composed of quartz and/or feldspar because these are the most common minerals in the Earth's crust. Like sand, sandstone may be any colour, but the most common colours are tan, brown, yellow,...
of the Lower to Middle Turonian
Turonian
The Turonian is, in the ICS' geologic timescale, the second age in the Late Cretaceous epoch, or a stage in the Upper Cretaceous series. It spans the time between 93.5 ± 0.8 Ma and 89.3 ± 1 Ma...
of the Cretaceous
Cretaceous
The Cretaceous , derived from the Latin "creta" , usually abbreviated K for its German translation Kreide , is a geologic period and system from circa to million years ago. In the geologic timescale, the Cretaceous follows the Jurassic period and is followed by the Paleogene period of the...
. They belong lithostratigraphically to the Weissenberg Formation (Bělohorské souvrství) in the Bohemian Cretaceous System. The nearby area surrounding the Tyssaer Wände to the north and south is covered by diluvial
Pleistocene
The Pleistocene is the epoch from 2,588,000 to 11,700 years BP that spans the world's recent period of repeated glaciations. The name pleistocene is derived from the Greek and ....
sediments of loam
Loam
Loam is soil composed of sand, silt, and clay in relatively even concentration . Loam soils generally contain more nutrients and humus than sandy soils, have better infiltration and drainage than silty soils, and are easier to till than clay soils...
, sand
Sand
Sand is a naturally occurring granular material composed of finely divided rock and mineral particles.The composition of sand is highly variable, depending on the local rock sources and conditions, but the most common constituent of sand in inland continental settings and non-tropical coastal...
and boulder-containing scree
Scree
Scree, also called talus, is a term given to an accumulation of broken rock fragments at the base of crags, mountain cliffs, or valley shoulders. Landforms associated with these materials are sometimes called scree slopes or talus piles...
.
In the sandstone are heavy concentrations of ferrous minerals on closely spaced strata, that can be identified from their yellow to red stripes of colour and predominantly horizontal. A striking feature in many places where the lower strata are visible are small and large cavities as well as occasional tunnels with an oval cross-section, whose walls are often covered with calcareous sinter
Calcareous sinter
Calcareous sinter is a freshwater calcium carbonate deposit, also known as calc-sinter. Deposits are characterised by low porosity and well-developed lamination. Calcareous sinter should not be confused with siliceous sinter, which the term sinter more frequently refers to...
deposits. These are relics of very old solution processes in the sandstone.
In zones of strong weathering
Weathering
Weathering is the breaking down of rocks, soils and minerals as well as artificial materials through contact with the Earth's atmosphere, biota and waters...
, the marked stratification over short distances is clearly visible. Features associated with cross-bedding
Cross-bedding
In geology, the sedimentary structures known as cross-bedding refer to horizontal units that are internally composed of inclined layers. This is a case in geology in which the original depositional layering is tilted, and the tilting is not a result of post-depositional deformation...
occur relatively frequently.
Sources
- Albrecht Kittler: Kletterführer Böhmische Schweiz - Raiza und Tyssaer Wände. Verlag Kittler, Dresden 2007
- J. Valečka (Red.): Geologická mapa ČR, List 02-23 Děčín. 1:50.000. Praha (ČGU) 1992, Signaturen 6, 7, 41, 43
- Radim Kettner: Allgemeine Geologie. Bd. 2. Berlin (Deutscher Verlag der Wissenschaften) 1959, S. 293