Various products of volcanic activity in the Neogene arc in the Carpathians (Slovakia)

As in the previous years, the autumn field trip of our Student Chapter represents the main annual educational event. This year, our target was to visit various products of volcanic activity in the Neogene arc in the Carpathians (Slovakia) and inspect their associated mineralization types, ranging from skarn to porphyry, mesothermal and epithermal styles.

During four days we were exploring different mineralization types associated with the evolution of the Miocene Štiavnica stratovolcano: gold mineralization of the intermediate-sulfidation type in Banska Štiavnica and Hodruša (museum and dump of the Rozália mine), magnetite skarns in Úškrtova Dolina, and secondary mineralization in L‘ubietová and Špania Dolina. We also had the opportunity to visit the secondary limnoquartzite deposits with plant remnants in the Kremnické Vrchy Mts.

The area is located in the western part of Slovakia. The Banska Štiavnica ore district is situated in the central zone of the largest stratovolcano in the Central Slovakian volcanic field of Neogene age, emplaced in the inner part of the Carpathian arc overlying the Hercynian basement. The volcanic activity was related to subduction of the flysch belt under the Carpathian arc and to subsequent back-arc extension.

An epithermal system related to the postcaldera uplift has the dominant significance in the metallogeny of the ore district. According to their ore assemblages, the epithermal veins were divided into three types:
1) base-metal veins
2) Au-Ag veins in the central or western part of the horst
3) Au-Ag veins related to marginal faults of the horst
Formation of the hydrothermal system and precipitation of Au mineralization is related to the initial stage of caldera subsidence that changed the hydrologic conditions.

SGA News No 32, page 3

Field trip to central part of Krušné hory Mts. (Erzgebirge)- Měděnec and Mýtinka location

The metamorphic complexes of the northwestern Bohemian Massif host several mineralization styles that span stratiform base-metal deposits, stratabound skarn mineralization as well as low-temperature hydrothermal veins.
During the second trip in 2012, our chapter visited several examples of these mineralization styles, exposed mainly in historical mines.

The Mědník deposit near the village Měděnec: calcic-ferroan skarn with stratabound sulfide mineralization, produced silver, copper and iron since medieval times. We also visited a Země zaslíbená mine of this mineralization in Měděnec.

Mýtinka location: about 4 km SW of Měděnec; a complicated fold structure containing migmatites, orthogneisses and mica schists intensely fractured and filled with quartz gangue. Quartz veins located at fault intersection are usually mineralized with hematite that formed from low-temperature hydrothermal fluids.

SGA News No 32, page 9

Field trip to locations of tin mineralization and alteration styles in the northwestern Bohemian Massif

Our SGA Student Chapter devoted its first field trip in 2012 to cassiterite mineralization and associated alteration in the northwestern part of the Bohemian Massif. We visited the Hieronymus mine at Čistá and the active quarry at Krásno.

The Čistá tin deposit:  the formation of postmagmatic greisens and late hydrothermal vein-type mineralization (Sn-W).

The active quarry at Krásno: open pit exploits alkali feldspar granites and alkali feldspathites as raw materials for ceramic, glass and chemical industry.

SGA News No 32, page 1

 

Field trip to the Most coal basin

Date: November 21, 2011
Program: visit to the Centrum black coal mine, the only underground mine in operation in the Czech Republic, visit to several mineral occurrences related to the Tertiary volcanic activity in the Northern Bohemia
Leader: Ing. Pavel Lička (North Bohemian Mining Corporation)

Field trip to ore deposits of the northeastern Bohemian Massif (Czech-Polish border)

Date: October 7-9, 2011
Program: Joint field trip of the Student Chapter Prague and the Baltic Student Chapter Cracow (Poland). Visit to principal ore and mineral deposits in the Silesian and Eastern Lugian domain (Zlaté Hory gold deposit, Zloty Stok gold deposit, Zlatý Chlum gold deposit, Žulová pluton – ore deposits on the contact with granitoids) and technical facilities related to exploitation of natural resources (the Dlouhé Stráně water pumping power plant).

in front of the Anseln mine

in front of the Anseln mine

Leaders: Kateřina Schlöglová, M.Sc. and Dr. David Dolejš (Faculty of Science, Charles University in Prague), Mr. Martin Hanáček (Silesian Museum of Nature and History in Opava), Dr. Miloš Ďuraj (Technical University Ostrava)

SGA News No 30, page 26

Field trip dedicated to ore and mineral deposits of the Fennoscandian Shield

Date: July 4-26, 2011
Program: visit to principal ore deposits and important geological localities in Sweden and Finland (Bergslagen skarn mining district, Skellefteå VMS mining district, Aitik porphyry-Cu mine, Kiruna mine, metallic mineralization in the Lappland Greenstone Belt, Pyhasalmi mine, Wyborg rapakiwi batholith, Alnö and Siilinjärvi carbonatites)
Organization: Dr. David Dolejš

SGA News No 30, page 21

Aitik open pit (N Sweden) with chief mine geologist Greg D. Joslin

Aitik open pit (N Sweden) with chief mine geologist Greg D. Joslin

Kiirunavaara iron mine (N Sweden)

Kiirunavaara iron mine (N Sweden)

SGA Student Conference 2011

logoPrague2011sga conference 2011

Organizing committee

Student Chapter Prague:

  • Prague Chapter President
    Kateřina Schlöglová;
    schloglo@gmail.com; sga.prague@gmail.com
  • Registration and abstract submission
    Jakub Trubač
  • Treasurer (conference fee payment)
    Lukáš Vondrovic
  • Field trips leaderspeople
    Luboš Vrtiška (Příbram) and Jan Bubal (Jáchymov)
  • Accommodation
    Zita Bukovská

Academic Advisors:

  • Dr. David Dolejš – Faculty of Science, Charles University
  • Dr. Anna Vymazalová – SGA Council, Czech Geological Survey

Abstract Volume & Fieldtrip Guidebook

SGA News No 29, page 20

Halle meeting

From February 19th to February 23rd 2010 a group of German SGA student members organized an international Student Meeting at the Martin-Luther-University Halle-Wittenberg. Students of the University of Prague (Czech Republic) and Germany (LMU Munich, TU Freiberg, MLU Halle) took the chance to meet with the students of Halle University, to get to know each other and possibly to start stronger international relations.

SGA News No 27, page 18

Non-traditional metallic resources in crustal metamorphic complexes

The last field trip in 2009 took place on 18-19th October in several localities of non-traditional metallic resources.

mine Rožná I

mine Rožná I

  • Mine Rožná I: uranium mineralization, alkali alteration style (underground visit)
  • Horní Bory: lithium-berylium mineralization in granitic pegmatities, visit to the quarry
  • Štěpánov nad Svratkou: supergene copper mineralization, visit to the Mír mine
  • Rožná: high-grade lithium pegmatite, visit to the pit
  • Dřínová near Tišnov

Lecture: Lukáš Vondrovic

 

Metallic and non-traditional resources of the Erzgebirge Mts., central Europe Metallogeny of the Saxonian Erzgebirge

In 27-29th September 2009 Prague Chapter visit many localities in Erzgebirge Mts. (classical ore district within the framework of Variscan orogeny and geodynamics).

  • Krupka: minor intrusions with distal Mo mineralization
  • Zinnwald-Altenberg: Sn-bearing greisen stockworks in a subvolcanic hydrothermal system, visit to pit and museum
  • Bergakademie Freiberg: joint meeting with the SEG chapter members, visit to educational underground facility and historical mineralogical collections
  • Ehrenfriedersdorf-Geyer: tin-mineralized high-level intrusions, underground, pit and museum visit
  • Schlema: uranium hydrothermal deposits related to deep-seated faults, underground visit
  • Johanngeorgenstadt: uranium mining, educational trail
  • Horní Blatná and Přebuz: sheeted tin-bearing greisens
  • Rýžovna: fossil tin-bearing placers
  • Tannesberg-Gottesberg-Schneckenstein: tin-tungsten mineralization in a subvolcanic rhyolite structure, underground visit, museum visit, geological field trip
  • Jáchymov: Ag-Co-Ni-U mineralization, underground visit to Svornost mine, radioactive springs
  • Horní Slavkov-Krásno: hydrolytic and alkali alteration styles in the high-level granitic cupolas, visit to open pits, mine dumps and mining museum

Lecture: David Dolejš, Jakub Trubač, Lukáš Vondrovic
SGA News 26, p.18