Příbram, Jáchymov (Czech Rep.) and Zinnwald (Germany)
October 25-27, 2016
In cooperation with BSc. Ondrěj Krátký from SGA Student Chapter (Charles University
in Prague) we have successfuly organized 3-day field trip dedicated to important ore deposits
in Czech Republic and Germany. Eleven SEG members and three non-members were
involved in this field trip led by Alexander Kubač and Tomáš Klučiar.
First day our group visited the mining museum in Příbram Ag-Pb-Zn-U deposit, which
is one of the most important regions of hydrothermal ore mineralization of the Czech
Republic. Total production of metals from this area was 388 t Ag, 518,000 t Pb, 70,000 t Sb
(Příbram base-metal ore district) and 47,400 t U (Příbram uranium ore district). The ore
deposits of the Příbram ore area had a long history of mining of silver and base-metal ores:
the beginning of mining dates back to the Middle Ages. The ore district is represented by the
main deposit of Březové hory, where the hydrothermal veins penetrate the Upper Proterozoic
slate and Cambrian sandstone and greywacke. The museum’s exhibits were built in the
original mine workings and administrative buildings and they show the rich mining past of the
region. At the beginning of exhibition our participans obtained some informations about
history and geology of this deposit (Fig. 1), followed by sightseeing tour of the mining area
(Fig. 2) and extensive mineralogical collection (Fig. 3). At the end of exhibition, students
were be able to collect some mineralogical and geological samples on the Ševčín shaft slag
heap (Fig. 4). Finally, our group visited the smelting plant in Lhota near Příbram where Prof.
Vojtěch Ettler, PhD. (Charles University in Prague) has provided us some valuable
informations about processing technologies and environmental impacts (Fig. 5).
The second day was dedicated to visiting of the former uranium mine in Jáchymov
(Krušné Hory Mts.). The whole deposit (including 30 shafts) belonged to the important source
of uranium and is localized in metamorphic mantle of granite pluton. At the beginning of the
20th century the radium element was discovered on the deposit and was the only known
source in the world. Hydrothermal veins are divided into weakly mineralized Morning (E-W
orientation) and ore-bearing Midnight (N-S orientation) veins. According to the number of the
main ore elements (Ag-Bi-Co-Ni-U) the mineralization is often so-called five-element
mineralization. After the short introduction to history and geology of the deposit our group
visited the Svornost shaft. Participants were able to see the mineralized vein structures and
geological settings on the 10th and 12th level (~450 m depth). Part of the excursion was
dedicated to showing us the radioactive spring with radium water, which has applications in
balneology nowadays (Fig. 6).
Later, our group visited the Zlatý Kopec („Gold Hill“) skarn deposit near Boží Dar,
which belongs to the Jáchymov ore district. Skarn formation was interpreted here by
metasomatism of lens-shaped bodies of calcareous sediments altered to marbles in chloriticsericitic phyllite complex. The main ore minerals are cassiterite, sphalerite, chalcopyrite and
magnetite. On the slag heap next to the Johannes adit participants had the opportunity to
collect some mineralogical samples of ore minerals. The second day of our field trip was
finished by visiting of discovery site of the pseudoleucite crystals near Loučná pod
Klínovcem village (Fig. 7).
The last day our group visited the greisen Sn-W deposit in Zinnwald, Germany. The
visiting of Tiefer-Bünau adit (Fig. 8-10) provides to our students the complex overview to
geology and mineralogy of this famous deposit. The visited deposit is a part of the historic
Cinovec-Zinnwald mining district. Over the past 600 years more than 40,000 tones of tin has
been extracted in this area. The deposit itself is related to post-orogenic granite intrusion,
which intrudes rhyolites. The pervasively altered and greisenised lithium-albite granite (with
quartz, topaz, zinwaldite and cassiterite) in the upper part of the cupola hosts flat veins
surrounded by greisens and steep quartz veins with wolframite. The main minerals are
cassiterite, wolframite, scheelite, zinwaldite, topaz and fluorite. Nowadays, the drillhole
research take place in Cínovec (Czech Rep.) for determining the Sn and W resources, where
our group had the opportunity to see the drillhole cores at the end of field trip.
This field trip could be organised thanks to the Stewart R. Wallace Fund as most of the
received funding was used to cover our expences directly connected with it.
References:
Ettler V., Sejkora J., Drahota P., Litochleb J., Pauliš P, Zeman J., Novák M., Pašava J. (2010):
Příbram and Kutná Hora mining districts – from historical mining to recent environmental
impact. Acta Mineralogica-Petrographica. Field Trip Guide Vol. 7, p. 9-19.
Ondruš P., Veselovský F., Gabašová A., Hloušek J., Šrein V. (2003): Geology and
hydrothermal vein system of the Jáchymov (Joachimsthal) ore district. Journal of the
Czech Geological Society, 48, p. 3-4.
https://www.muzeum-pribram.cz/en/mining-museum-brezove-hory/tour-sites/site-a-thesevcin-mine/
http://www.europeanmet.com/projects-cinoveclithiumtinproject.html
http://www.geopark.cz/en/zlaty-kopec-hill
http://www.laskaksutrum.cz/leucit-z-loucne-pod-klinovcem/
http://www.besucherbergwerk-zinnwald.de/index.html
Fig. 1. Commentary to history of the Příbram Ag-Pb-Zn-U deposit, Czech Republic.
Fig. 2. Visiting the mining
museum in Příbram Ag-Pb-Zn-U
deposit, Czech Republic.
Fig. 3. Native silver from Příbram Ag-Pb-Zn-U deposit, Czech Republic.
Fig. 4. Sample collecting on the Ševčín shaft slag heap,
Příbram Ag-Pb-Zn-U deposit, Czech Republic.
Fig. 5. Commentary to environmental impacts near smelting plant in Příbram,
Czech Republic.
Fig. 6. Radium water using in balneology, 12th level of the Svornost mine,
Jáchymov, Czech Republic.
Fig. 7. Discovery site of the pseudomorphs after leucite crystals
near Loučná pod Klínovcem village, Czech Republic.
Fig. 8. Field trip participants in front of the Tiefer-Bünau adit
in Zinnwald greisen Sn-W deposit, Germany.
Fig. 9. Commentary to geology in Tiefer-Bünau adit,
Zinnwald greisen Sn-W deposit, Germany.
Fig. 10. Extracted spacescape in Tiefer-Bünau adit,
Zinnwald greisen Sn-W deposit, Germany.