Rabengebirge
| Rabengebirge
Góry Krucze, Vraní hory
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 View of the western flank of the Czech part of the Raven Mountains with the Královecký Špičák roughly in the middle of the picture |
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| Highest peak | Královecký Špičák ( Königshaner Spitzberg ) ( 880.6 m nm ) | |
| location | Czech Republic , Poland | |
| part of | Sudeten | |
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| Coordinates | 50 ° 39 ′ N , 15 ° 59 ′ E | |
| rock | predominantly Rhyolite | |
| Age of the rock | Unterperm | |
The Rabengebirge (Polish: Góry Krucze ; Czech: Vraní hory ) in Poland and the Czech Republic is a small, north-south running mountain range of 15 kilometers on the western edge of the Central Sudetes . To the west of the Rabengebirge lies the Liebauer Tor or Königshaner Pass (Polish: Brama Lubawska , Czech. Lubavská brána , to Královecké sedlo ), a depression running in north-south direction (524 m above sea level), which acts as the border between the central Sudeten and West Sudeten applies. The Rehorn Mountains and the Giant Mountains join to the west of the Liebauer Tor and the Landeshuter Kamm ( Rudawy Janowickie ) to the northwest .
geography
The Rabengebirge shows an almost teardrop-shaped outline on the map. It is a little over 4 km wide in the south and tapers to a narrow ridge to the north. Most of the Raven Mountains are in Poland , but it has its highest peak in the Czech part in the southwest. At its feet lie the town of Lubawka ( Liebau i. Schlesien ) and the towns of Krzeszów ( Grüssau ) and Chełmsko Śląskie ( Schömberg ) in Poland and the towns of Královec ( Königshan ) and Bernartice ( Bernsdorf ) in the Czech Republic . The northern foothills of the Rabengebirge are also known as the Uber Mountains. In Poland, the mountain range is counted due to its volcanic origin together with similar mountain ranges in the area to the southern part of the Waldenburger Bergland .
The highest elevations are the Královecký Špičák ( Königshaner Spitzberg ) with 881 m nm and the Szeroka ( Wide Mountain ) with 844 m nm The Krucza Skała ( Rabenstein ) (681 m) is particularly striking .
geology
The relief of the Rabengebirge is determined by volcanic rocks , especially rhyolite , which solidified from magma and lava in the earliest Permian , near the end of the ancient world . These volcanic rocks represent the most recent phase of the permocarbonic , late and post-Variscan volcanism of the Inner Sudetian Depression , a fossil intramontane sedimentary basin of the Variscan Mountains or the u. a. resulting Bohemian mass . The Rabengebirge is located at the northwestern end of the Inner Sudetian Depression in the so-called Krzeszów-Brachysynklinale n. According to Czech lithostratigraphy, the volcanic rocks are in the higher part of the Nowa-Ruda subformation of the Broumov formation, according to Polish lithostratigraphy between the Słupiec formation and the Radków formation ( Polish Rotliegend ). The thickness of the volcanic succession is up to 700 m in the south (especially west of Chełmsko Śląskie ) and at least 200 m in the north of the Raven Mountains. In the region west of Chełmsko Śląskie, the main chimney of the early Permian volcano is assumed. To the northeast outside the Raven Mountains near Czarny Bór , the volcanic rocks are still 50 m thick.
A significant outcrop of the volcanic rocks of the Raven Mountains can be found on the Czech side in the form of a large quarry on the western slope of the northern neighboring mountain of the Königshaner Spitzberg (Královecký Špičák). The alkali irhyolite located there ( ⊙ ) and penetrated by trachy dacite / trachy andesite veins (see TAS diagram ) has been dated to an absolute age of around 297.13 million years using the uranium-thorium method .
In general, the rhyolite of the Rabengebirge is described as a predominantly massive, yellowish to reddish, sometimes also greyish rock with a fine porphyry to aphanitic structure. The only 1–2 mm large phenocrysts of the porphyry variant consist of plagioclases and alkali feldspars as well as pseudomorphoses of kaolinite and opaque minerals, presumably pyroxenes . The matrix consists mainly of xenomorphic quartz and alkali feldspars with a relatively high proportion of finely divided hematite . The laminated rhyolites, which occur mainly in the south of the Raven Mountains, show flowing textures. In the upper part and the marginal areas of lava flows, the rhyolite often has filled bladder cavities (amygdaloid structure, "almond stone") and is associated with various forms of breccias .
Attractions
The geological nature reserve Kruczy Kamień is located on the northern slope of the Rabenstein, between Lubawka and Chełmsko Śląskie . It occupies an area of 10.21 hectares, was launched in 1954 and offers volcanic rock walls with heights of up to 30 meters, rock formations, rare plant species and the so-called Dolina Miłości ("Valley of Love"), a romantic riverbed.
Web links
Individual evidence
- ↑ a b Radovan Vlček: Geology for everyone (Czech-Polish geological educational trail). Středisko ekologické výchovy SEVER, Horní Maršov 2014, p. 3 ( sever.ekologickavychova.cz PDF 24.8 MB)
- ↑ a b c d e Tomasz Bartuś: Kruczy Kamień. The Raven Stone. P. 79–82 in: Tadeusz Słomka (Ed.): Catalog geologicznych stanowisk dokumentacyjnych i obiektów geoturystycznych w Polsce. Catalog of the documentation stands and geoturistic objects in Poland. AGH Akademia Górniczo-Hutnicza, Kraków 2012 ( agh.edu.pl PDF 660 kB)
- ↑ a b Stanislav Opluštil, Mark Schmitz, Václav Kachlík, Stanislav Štamberg: Re-assessment of litostratigraphy, biostratigraphy, and volcanic activity of the Late Paleozoic Intra-Sudetic, Krkonoše-Piedmont and Mnichovo Hradiště based on basins (Czech-) Republic Pb CA-ID-TIMS ages. Bulletin of Geosciences. Vol. 91, No. 2, 2016, pp. 399–432 ( geology.cz )
- ↑ cf. Leszek Kurowski: Fluvial sedimentation of sandy deposits of the Słupiec Formation (Middle Rotliegende) near Nowa Ruda (Intra-Sudetic Basin, SW Poland). Geologia Sudetica. Vol. 36, 2004, pp. 21-38 ( geojournals.pgi.gov.pl )