Smrčí u Semil

General Characteristics

County (administration): Liberecký kraj
District (town): Semily
Village: Záhoří
Cadastre: Smrčí u Semil
Map sheets: 03-32 Jablonec nad Nisou, 03-324 Turnov
Accessibility: special entry permit necessary (military area, quarry, private land)
Technical object: quarry
ID: 559

Geology

Short characteristics of the site: Active wall quarry in an extensive Tertiary volcanic complex composed of basaltic lava (basanite) containing mantle xenoliths ("olivine nodules"). The lava flow overlies a high gravel terrace of the Jizera River and has been dated to the Pliocene (approximately 4.5 million years ago). The quarry exposes a unique profile of a so-called rootless crater, formed by steam explosions generated when hot lava flowed over water-saturated fluvial terrace gravels. Particularly remarkable are the abundant olivine nodules (ultrabasic xenoliths containing gem-quality olivine, chrysolite), derived from rocks of the Earth's upper mantle. The rock displays well-developed columnar jointing. Mining operations have not yet been completed.
Regional geologic unit: Bohemian Massif > Tertiary > Tertiary - scaterred relics of alkaline Volcanics
Stratigraphy: Tertiary
Subject: petrology, volcanology, mineralogy, economic geology
Geological phenomenon: stony organ, lava flow, mineral
Genesis: volcanic
Rock: basanite

Territorial protection

Level of protection: Registered geological localities suggested for protection
Part of national geopark: Bohemian Paradise
Conflicts of interests: reclamation, open cast mining

References

FARSKÝ, F. (1876): Mineralogische Notizen I. Mineralien aus der Kosakover Basaltkugeln. – K. kön. Geol. Reichsanst., 205–208.
Chaloupský J., Teisseyre, H., 1968: Geology of the West Sudeten. - Guide to Excursion 8 AC, International geolog. congress, XXIII session, Prague 1968, str. 14. Praha.
FEDIUK, F. (1968): Ad¬ditional notes on the basaltic volcanics and their ultrabasic nodules at Smrčí in the Želez¬ný Brod area. – Rotaprint, Přír. fak. univ. Karlovy, 1–12.
Raprrich, V., red. (2011): Základní geologická mapa České republiky 1 : 25 000 s Vysvětlivkami 03-324 Turnov. - Česká geologická služba. Praha.
ACKERMAN, L. – MAHLEN, N. – JELÍNEK, E. – MEDARIS, G. JR. – ULRYCH, J. – STRNAD, L. – MIHALJEVIČ, M. (2007): Geochemistry and evolution of subcontinental lithospheric mantle in Central Europe: Evidence from peridotite xenoliths of the Kozákov Volcano, Czech Republic. – J. Petrol., 48, 2235–2260
PAULIŠ, P. (2000): Nejzajímavější mineralogická naleziště Čech. Kutná Hora, 59.

Elaboration and Updating

Elaborated by: Jan Drozen, 30.10.2001
Updated by: Dašková Jiřina, 25.10.2001, Gürtlerová Pavla, 08.01.2012, Rapprich Vladislav, 31.08.2012, Vajskebrová Markéta, 17.06.2026

Citation

The database Important geological localities of the Czech Republic: 559 [online]. Prague: Czech Geological Survey, 1998 [cit. 2023-06-16]. Available from: https:// lokality.geology.cz/559.

Location in map:

Assessment

Scientifical assesment: great
Educational assesment: middle
Significance: supraregional
Representativeness: major
Geological importance: significant study profile, geoturistic value
Locality conditions: no problems

You can send information about a change in the status of the site to lokality@geology.cz