Malý Uran
General Characteristics
County (administration):
Středočeský kraj
District (town):
Rakovník
Village:
Oráčov, Jesenice
Cadastre:
Kosobody, Oráčov
Map sheets:
12-13 Jesenice, 12-134 Oráčov
Accessibility:
passable footpath
Technical object:
waste dump
ID:
2790
Geology
Short characteristics of the site:
West Bohemian Neoproterozoic, Barrandian. Natural outcrops of alum shales. They are deeply weathered and disintegrated into fragments. Alum shales were exploited in the past. Nature Monument, protecting interesting vegetation with abundant juniper. The name od the locality is after the former uranium exploration mine called Kosobody 1 from the 1950s. The locality (heaps along the mine) is marked as Kosobody 1, situated about 70 m from the edge of a relatively sparse oak forest. The area affected by mining work is about 60x30 m large. There is a heap of about 15x15 m, about 5 m high, on a gentle slope. The heap is dominated by 99% fresh fragments (10-25 cm) of dark gray, sometimes finely laminated shale of neoproterozoic age. Fragments of dark porphyry with growths of quartz (probably granite porphyry) and fragments of gray quartz are rare. The heap has only slightly increased radioactivity. Above the heap is about 20 m long and up to 2 m deep partially overgrown and sunken notch, in the direction of 170 °, most likely a trench dug along the reddened zone. The material around the yard has the highest activity in the whole locality. The measurement showed: K = 3.4 wt. %, U = 112 ppm, Th = 7.4 ppm, magnetic susceptibility varies between 0.10-0.17 x 10-3 SI. About 10 m above this groove is a transverse groove roughly in the V-Z direction about another about 10-15 m further in the same direction. These are transverse grooves, in the direction of mineralization there is an increased radioactivity, but only weakly. The rocks are heavily weathered and clayey material - clay and fragments up to about 7 cm. These are heavily weathered shales or breccias, perhaps in places quartzite, covered with yellow weathering crust in places of probable jarosite. Of the minerals, torbernite, less metatorbernite, was formed in the weathered vein, forming apple green flakes up to 1 mm.
Regional geologic unit:
Bohemian Massif > Bohemicum > Barrandien
Stratigraphy:
Proterozoic
Subject:
geology, botany, economic geology, mineralogy
Geological phenomenon:
rock, ore mineralization, vein
Genesis:
metamorphic (general metamorphism), anthropogenic (anthropogenic activity)
Rock:
slate, schist
Territorial protection
Level of protection:
Nature monument
Additional information:
See the Digital register of the Agency for Nature Conservation and Landscape Protection of the Czech Republic AOPK ČR, code 1830 (Malý Uran)
Conflicts of interests:
without conflicts
References
- Ložek V., Kubíková J., Spryňar P. a kol.(2005): Střední Čechy. In: Mackovčin P. a Sedláček M.(eds.): Chráněná území ČR, svazek XIII. Agentura ochrany přírody a krajiny ČR a EkoCentrum Brno, Praha str.518
Elaboration and Updating
Elaborated by:
Pavla Gürtlerová, 26.05.2007
Updated by:
Gürtlerová Pavla, 31.05.2007, Žáček Vladimír, 13.03.2021
Citation
The database Important geological localities of the Czech Republic: 2790 [online]. Prague: Czech Geological Survey, 1998 [cit. 2023-06-16]. Available from: https:// lokality.geology.cz/2790.
Location in map:
Assessment
Scientifical assesment:
medium
Educational assesment:
middle
Significance:
regional
Representativeness:
middle
Geological importance:
geo-regional value (mapping)
Locality conditions:
no problems
You can send information about a change in the status of the site to lokality@geology.cz
