General Characteristics

County (administration): Liberec Region
District (town): Liberec
Cadastre: Zábrdí u Osečné
Map 1 : 50 000 (sheet No): 0331, 03312
Geological region: Czech Cretaceous Basin - Jizera Cretaceous & Cretaceous of the lower section of Labe River, Ploučnice, Kamenice and the Děčínský Sněžník Mt.
Accessibility: - access without footpath
ID : 3401

Geology

Short characteristics of the site: The locality displays an outcrop and surrounding blocky scree. The volcanics are exposed forming a part of well known morphological and petrological phenopmena. This described locality forms an extrusive part of the volcanic ridge called "Čertova zeď - the Devil´s Wall". The depression in this ridge resembles a maar but is without lacustrine sediments. Only pyroclastic deposits occur being surrounded by compacted Cretaceous sediments of the Jizera Formation. The whole ridge represents in fact dyke of polzenite. The rock is transected by calcite veins, contains phenocrysts of biotite and possibly also of wollastonite. The rock is intensively weathered in places where iron oxide nodules were formed. Regionallly this locality belongs to the disseminated alkali volcanics of the Bohemian Massif.
Regional geologic unit: Bohemian Massif - superficial deposits and post-Variscian magmatites - Tertiary - Dispersed Alcalic volcanits
Stratigraphy: kenozoikum - terciér (paleogén - neogén), mezozoikum - křída - svrchní křída
Subject: volcanology, petrology
Geological phenomenon: dyke, volcaniclastic deposits, characteristic rock
Genesis: volcanic
Rock: polzenite

Territorial conservation

Level of protection: Registered geological localities suggested for protection
Protection of a geol. phenomenon: B - Geological phenomenon is the reason for a recommendation to the protection
Conflicts of interests: without conflicts

References

PALUSKA, Antonín & VESELÝ, Pavel (2010): Návrh na rozšíření chráněné oblasti Národní přírodní památky „Čertova zeď“ v severních Čechách (Český Dub-Osečná) a vytvoření chráněné oblasti „Velká Čertova zeď“.- 2. vulkanologický seminář odborné skupiny vulkanologie České geologické společnosti v Teplicích,Speciální publikace Regionálního muzea v Teplicích, str. 35-36.

Elaboration and Updating

Elaborated by: Gürtlerová Pavla, 07.02.12
Updated by: Gürtlerová Pavla 24.03.14, Kukal Zdeněk 25.09.17, Krejčí Zuzana 26.09.17, Vajskebrová Markéta 29.09.21

Citation

The database Significant geological localities of the Czech Republic: 3401 [online]. Prague: Czech Geological Survey, 1998 [cit. 2024-04-25]. Available from: http:// lokality.geology.cz/3401.

Location in map: