Prague SGA Student Chapter visiting Columbia-Bogotá SGA Student Chapter: Mineral deposits of Columbia

Štěpán Jaroměřský, Ivan Mateo Espinel Pachón, Jan Hofmann, Milton A. Santos

1SGA Student Chapter Prague, Faculty of Science, Charles University, Albertov 6, 128 43 Prague 2, Czech Republic; jaromers@natur.cuni.cz

Photo of the whole group of participating members

As every year, Prague Chapter participates in several fieldtrips with friendly chapters. This year, we managed to negotiate several daily fieldtrips with the SGA Student Chapter Columbia-Bogotá, which should have focused on emerald and gold deposits. The main target was to visit the world famous emerald deposit near the town of Muzo. However, the whole program was charged and very well prepared by the Colombia-Bogotá Chapter. The Prague chapter was represented by 10 members and the field trip lasted from March 19 to 25.

1st day:

On the first day we visited a sedimentary-exhaliative deposit (SedEx) near Chiquinquirá – Boyaca. Sedex are ore deposits formed by a release of ore-bearing hydrothermal fluids. Subsequently, they must be released into a water reservoir, resulting in the precipitation of stratiform ore. SedEx deposits are the most important sources of lead, zinc and barite. These ores are processed for tungsten, copper, silver, gold and bismuth.

This deposit is located high in the mountains of northern side of central Colombia. 10-year-old exploration galleries designated for researching copper in the past surround the site. There are abundantly chalky sediments, in which there are minerals of copper such as chalcopyrite. We also found some beautiful examples of barite crystals. It is a fairly extensive site, but because of the steep slope and dense fog, we stayed on the upper parts of this deposit. It was a nice introduction to Colombian geology and nature.

2nd day:

On the second day, our emerald trip started in Las Pavas area. We had accommodation in the town of Muzo, from where a very narrow path led through the local mountains. Muzo itself is well known for its emerald deposits.

Emeralds are usually found in calcite-dolomitic veins containing pyrite, ankerite, albite and quartz. These veins are the product of hydro-thermal fluids that disrupt the rock massif and the interactions of the metasomatic fluid with subsequent deposition in the breaks formed by these calcite-dolomitic veins. It is likely that metasomatic fluids come from shale formations near Muzo, which are probably the source of vanadium, which is the cause of the unique color of local emeralds.

Firstly, we headed to the Rio Magdalena where we could find some samples in the river or meander scrolls. Only one member of our chapter was lucky enough to find a small sample in the shale. We even investigated one closed mine which might be reopened in the near future.

Fine emeralds crystals from Muzo. Photo by E. Vrňatová

3rd day:

On the third day, we had a scheduled visit to El Líbano Tolima, the El Porvenir gold mine, orogenic and epithermal gold deposit. This mine is processing sulphide ores like pyrit, containing relatively large amounts of gold (up to 1000 ppm). The grains of gold in the bearing are mainly included in sulphides and silicates. The mineralization of gold in the bearing is probably caused by the penetration of porphyres into the Paleozoic slate on the eastern wing of Colombian Andes. It is believed that the mineralization of gold occurred in three early phases of intrusion, which are accompanied by a number of sodo-calcical changes and the late phase of penetration of porphyres. The samples contained high quartz and chalcopyrite content.

We travelled to the mine a long way on a car’s hull. Then we went through the inspection, which was waiting for us in front of mine. The whole mine is active and so we could only be there in the pause period. The whole visit was fantastic and very engaging. At the end, everyone could take only one sample of the size of a fist.

One of the eight entrace to the El Porvenir gold mine

4th day:

On the fourth day, we visited the Cu-skarn Payandé deposit with garnets.

The post-Triasic plutonic rocks, known as the Payande Stock, grow on the eastern edge of Colombian central Cordillery near San Luis-Tolima. The quarry could not be reached directly by our bus, so we had to stretched our legs. At least we were accompanied by a car that eased us from our backpacks and hammers. The road was not difficult, except from the ford across the river, where we had to take off our shoes and wade.

The reason why we drove there were skarn outcrops, where the great and beautiful crystals of andradite are located. Regarding the other minerals, hematite, azurite, quartz, calcite, chlorite, magnetite and sphalerite are also found here. Petrology and mineralogy is very interesting in this deposit, as there are signs of a passage of hydrothermal fluids and changing contacts with individual minerals. We saw the beautiful mineralization of the copper. There are also several zones to see. The first zone corresponds to the tonalites, the second to endoskarns and the third to exoskarns. There is also a prograde zone containing garnets and pyroxenes. In the retrograde zone, where iron oxides, iron sulphates and copper are found. This was our last locality in terrain.

5th day:

On the fifth day we were back in Bogóta and we had a planned tour of the geological section at the Universidad Nacional de Colombia. We went through some local classrooms and looked at a few samples from the local collections. We also examined a few rocks which we saw during the fieldtrip under a microscope and finally we listened to short presentations from Prague Chapter and Bogota Chapter. After exploring the area, we went to the city to taste a bit of all possible and impossible fruits on the world-famous market Plaza de Paloquemao. Then we moved to the Gold Museum in Bogota and the largest Emerald museum in the world. Unfortunately, this day the Emerald Museum was closed in, so we had to visited another day.

Finally, we would like to thank all the leaders of this fieldtrip, especially Ivan Mateo Espinel Pachón and all the SGA Student Chapter Columbia-Bogotá members for an amazing organization and for ensuring everything needed for the success of fieldtrip. In general, I think that the cooperation between Chapters is the best form of studying. Also I would like to express great thanks to the whole SGA, as it would not be organized without their support and many thanks to all our sponsors, such as Vitana or Severočeská doly.

I think that this fieldtrip to Columbia strengthened the connection between our SGA student chapters and we hope that despite the distance between Prague and Colombia we will continue to collaborate and exchange experiences.

Tasting of Colombian fruit delicacies by J. Bašus

17th Freiberg short course in economic geology 1.-4.12. 2019

Každoroční Short Course ložiskové geologie ve Freibergu. Letošní program na téma: Iron and Manganese Ore deposits.

Mezi dalším programem se můžete těšit na uvítací ice-breaker party v ložiskových sbírkách TU Bergakademie Freiberg, možnost navštívit výstavu Terra Mineralia a užít si sváteční atmosféru na vánočních trzích.

https://tu-freiberg.de/fakult3/min/econgeology/short-courses
Bližší info a registrace dle pokynů v emailu.

SGA Chapter Prague: Oncoming Colombia field trip

Prague Chapter SGA most anticipated event of 2019 is undoubtedly journey to Colombia. Members of our chapter are preparing geological field trip in cooperation with SGA Chapter from Bogota.

Our members have the unique opportunity to visit Colombian gold deposits and exclusive emerald mine of MUZU!

Do not miss a chance of your lifetime to visit rich deposits of beautiful Colombia and getting to know more SGA members around the world!

For more information stay updated with our newsletter.
Your SGA team



Field trip: Heritage stones of central part of Bohemian massif

This field trip was focused on visits of heritage stone deposits and it’s following processing. During trip were visited quarries Přibylov (siltstones), Škrovád (sandstones), Prachovice (limestones, marble, schists), also historical town Chrudim and its historical heritage stone sights and Lipnice nad Sázavou town with visit of local sculptor and his work. Leader: RNDr. Barbora Dudíková Schulmannová (Czech Geological Survey)

Traditional autumn field trip: Various metal, precious stone and heritage stone deposits of central and east Slovakia

1 st day: Dřínová quarry (duplex structure with nice samples of barites in limestones) and visit of mineralogical exposition in gallery Patriot in Tišnov.
2 nd day: Špania Dolina area in the central Slovakia (heap with celestines samples, Piesky locality with azurite samples and Richtarova loc. which is type locality for deviline) and visit of Dobšiná with ongoing research of Ni and Co deposits.
3 rd day: Gretla (spekularite and goethite deposit), Novoveska huta (heap Bartolomejka with tyrolite and other Cu secondary minerals) and mine Josef close to Dubnik, where is gem quality opal deposit.
4 th day: open pit mine Fintice close to Přerov (andesites with zeolite samples)
Leader: Bc. Jakub Mysliveček (Czech Geological Survey)

photo by Ľubomír Kyrc

photo by Ľubomír Kyrc

Report from the Gold Short Course 2018 (led by Prof. David. I. Groves) + post-course field trip in Bohemian Massif

Report from the Gold Short Course 2018 (led by Prof. David. I. Groves) + post-course field trip in Bohemian Massif

Jan Kulhánek, Marek Tuhý, Dominik Brém, Rafael Baieta

SGA Student Chapter Prague, Faculty of Science, Charles University, Albertov 6, 128 43 Prague 2, Czech Republic; jan.kulhanek@natur.cuni.cz

Photos album links:
Gold short-course: https://www.zonerama.com/SGA-Prague/Album/4347282
Post-Gold course Field trip: https://www.zonerama.com/SGA-Prague/583718

Short Course

During 19–20th of May 2018 the SGA Student Chapter Prague organized the Gold Short Course led by Prof. David I. Groves from the Centre for Exploration Targeting, UWA, Australia. There was an icebreaker organised in the Chlupáč’s Museum of Earth History in the Faculty of Science, which was a great opportunity to experience this newly established exposition with a glass of wine (Fig. 1). This event also took place in the Faculty of Science, Charles University, Prague, Czech Republic, where 77 participants from 13 countries and 6 SGA Student Chapters came to attend lectures by Prof. Groves (Fig. 2, 3).

David I. Groves is an Emeritus Professor at the University of Western Australia (UWA). He is considered to be a world leader in the research of ore deposits, particularly orogenic gold and IOCG deposits, and global metallogeny. On the UWA, he helped to establish the Centre for Exploration Targeting. He has authored and/or co-authored more than 500 publications, mainly in the fields of Archean evolution, komatiite-associated Ni-Cu deposits, orogenic gold deposits, the role of lithosphere in global metallogeny, and prospection mapping. He was elected President of the SGA, SEG and the Geological Society of Australia, and for his outstanding achievements during his career, he received both the SGA Newmont Gold Medal and the SEG Penrose Gold Medal.

Each day of the short course was focused on different topics within 4 lectures:

1st day – Orogenic gold deposits:

1st lecture: Introduction to orogenic gold

2nd lecture: The crustal continuum and genetic models for orogenic gold

3rd lecture: Critical factors controlling the formation of orogenic gold

4th lecture: Exploration targeting for orogenic gold

2nd day – Gold deposits on craton margins:

5th lecture: Introduction to intrusion-related gold deposits (IRGDs)

6th lecture: Nature of hybrid magmas and genesis of IRGDs

7th lecture: Carlin-type gold deposits of Nevada and China

8th lecture: Iron-oxide copper-gold deposits: nature and genesis

SGA Student Chapter Prague is grateful and would like to thank Prof. Groves for leading this short course and we would also like to thank all our sponsors who supported us during the organization of this event. Especially the SGA Educational Fund for the financial support and the bakery Kabát, butchery Göergl, company Vitana and brewery Staropramen for their excellent catering (Fig. 4).


Fig. 1: Ice-breaker visits of Chlupáč’s Museum of Earth History. Photo by V. Santolík.


Fig. 2: Ongoing lecture by Prof. Groves. Photo by V. Santolík.

Fig. 3: Group photo of all participants by V. Santolík.


Fig. 4: Food provider Michal Čurda with refreshments and sponsors logo. Photo by M. Tuhý.

Field trip

The post-course field trip took place during 21–23rd of May 2018 to various deposits in the Bohemian Massif. On this trip participated 14 SGA members, besides the Prague Chapter’s members also the Baltic, Black Forest and Moroccan members + SGA members without chapter.

1st day

We visited the Jílové gold district, which is characterized by three main types of gold-bearing ore bodies differing in morphology: ore veins representing the main type of mineralization mined in the past, gold-bearing stockworks representing the type of mineralization of greatest economic importance and stockworks of irregular shapes passing into impregnation zones which are developed at the eastern margin of the albite granite body between the Šlojíř and Kocoury vein zones, forming the Klobásy ore zone in the southern part of the Jílové district (Pepř mine). Firstly, we have visited two historical galeries, St. A. Paduán (Fig. 5) and St. Josef gallery, where it was possible to see historical styles of mining. Afterwards we moved to the more recent Pepř mine with Václav gallery which was finished during the second half of 19th century when the underground exploration of the southern part of the Jílové district occurred. Since 2012, this mine is under control of the Montanika society, who is removing the obstacles and taking care of the mine and to whom we would like to thank for an excellent visit, especially to the leader of this mine-tour Dr. Pavel Škácha (Fig. 6).


Fig. 5: Historical gallery St. A. Paduán. Photo by L. Kyrc.


Fig. 6: Introduction speech by Dr. Škácha in front of Václav gallery. Photo by L. Kyrc.

2nd day

We moved to the Krušné hory Mts. on the NW part of the Czech Republic and, in the morning, we visited the historical town Jáchymov, which is an old well-known mining district operating since 1511. In the beginning, silver was mined in secondary cementation zones and in 1519, the first Šlik’s Thaler was minted. This name was then transformed into the currency dollar. During the 16th century, 350 tons of silver were obtained. In the 19th century, this was the deepest mine in the world (665 m). After the discovery of uranium,local mines produced high quantities of this element and it was used mainly for glass and ceramics coloring. After the discovery of radium and upcoming radium rush, the first radium spa was established (1906) which is still in operation. Because of this, Svornost mine, is still operating and pumping the radioactive waters used for healing treatments (Fig. 7). Jáchymov ore district is a typical example of the five-element formation Ag-Co-Ni-Bi-As and U-formation formed as a medium temperate vein hydrothermal deposit in the Czech part of the Krušné hory Mts. (Erzgebirge). Up to 430 minerals, both primary and supergene, have been discovered and described in Jáchymov up to now (latest figure counted by J. Plášil in February 2011). After the mine tour, we also visited a local museum with a beautiful mineralogical collection from this area and with historical insight to the Jáchymov town.

The next stop was the historical mine Mauritius (Fig. 9) located near the town Horní Blatná, which has been an important mining center for the past several centuries, mainly for tin, and secondly for silver, iron, cobalt and later manganese ores. The mine was closed in 1944 and today provides well preserved historical galleries mined from the end of 16th century. The occurrences of tin ores are bound to the biotitic granites of the Blatná massif that build the wider neighborhood of the Blaten Hill. The granites are greisenized and enriched with mica, tourmaline, quartz, chlorite and especially cassiterite.

Close to the borders with Germany, we visited a skarn deposit called Zlatý Kopec, which is a lens-shaped body of diopside- and diopside-actinolite skarn in a chlorite-sericite phyllites complex. Ore minerals are cassiterite, sphalerite, chalcopyrite, and magnetite, which we had the opportunity to collect on the heaps near the gallery Johannes.


Fig. 7: Taking bath in warm radioactive spring Běhounek directly in Svornost mine more than 500 m below the surface level. Photo by L. Kyrc.


Fig. 8: Group photo in front of Svornost mine. Photo by L. Kyrc.


Fig. 9: Introduction talk in Mauritius mine. Photo by L. Kyrc.

3rd day

On the last day, we firstly visited an open-pit mine and processing of gem-quality pyropes, which are famous under the name “Czech garnet”. Czech garnet separating plant and the open-pit mine (Fig. 10), called Panské jámy, are situated close to the Podsedice village in the České Středohoří area (Central Bohemian Uplands – a neovolcanic field on the north of Czech Republic). There are approved reserves with a garnet content of about 40 g/m3. Garnets are mined easily by excavators from alluvial sediments, but originally, garnets come from near volcanic spots (diatremes), whose breccia filler contains blocks of serpentinized peridotite rich in those garnets. After separating garnets with the proper size and quality, they are sent for cutting and are used in the famous jewellery made by the company Granát Turnov.

After the garnets, we moved to the northern part of Krušné hory Mts., where we visited Krupka town surroundings in one of the youngest mining districts in this area named Knöttel (Bohosudov) situated on the east of Krupka area. The underground mining in this region, started in the 18th century. The deposit was formed in gneisses and was mainly exploited for tin and molybdenum mineralization. We started our tour close to the Barbora gallery, one of the molybdenum mine galleries exploited during World War 2. Then, we stopped near Siebenschläfer, a modern gallery with tin, copper and bismuth mineralization mined mainly for cassiterite. Next stop was on an old heap with high contents of native bismuth accompanied by chalcopyrite (Fig. 11). Another nearby stop was the Zwickenpinge, an open-pit with small shafts and heap with secondary copper mineralization and the first place of surface mining of tin and copper ores originated in 13th century. We also visited an open-pit above Prokop gallery, molybdenum mine with quartz body and greisen vein with occurrences of molybdenite, fluorite, topaz etc. The last stop was at the place where the quartz vein called Lukáš surfaces and where it was possible to find samples of green apatite crystals up to 1 cm, tin-rich mica zinnwaldite and some fluorite crystals.

Finally, we would like to thank all the leaders of the separate trips, especially to Dr. Pavel Škácha from the Pepř mine in Jílové district and Dr. Jakub Plášil and Dr. Viktor Goliáš for leading the trips to Svornost mine in Jáchymov. Special thanks to the Svornost mine and company Granát Turnov for allowing us to explore their mines and also to all the sponsors mentioned above.


Fig. 10: Collecting of small gem-quality pyropes in the open-pit mine near Podsedice village. System of cascades for cleaning processing waters. Photo by J. Mysliveček.


Fig. 11: Collecting samples on the heap rich on native bismuth. Photo by J. Mysliveček.

16 th Freiberg Short Course in Economic Geology – meeting with Representatives of Baltic Chapter and SGA members from Germany

Traditional SGA event in Freiberg is happening this year. Short Course´s title being Zinc Deposits. TU Bergakademie Freiberg is presenting premiere host speakers in the field of Zinc economical geology in four days of lectures.
The Short course will be hosted as usually in the academy interiors. Event organisers will traditionally meet us at icebreaker welcome party in academy´s ground.
For more detail info via email.
Your SGA Team

Faculty of Science, Charles University in Prague, Albertov 6- Whereabouts, transport, dining etc.

This article is a short guide for Prague newcoming visitors. Given information should help to navigate you around and also help you to find a suitable way to the faculty at Albertov 6,or other significant waypoints during your visit.

1) Vaclav Havel Airport- Faculty of Science, Albertov 6

The airport is located on the outer east side of the city, the way to the Faculty can take up to an hour. In case you head to your accomodations first, follow this instruction to get to the underground metro station line and customize your path afterwards. Faculty is several minutes from Tram station Albertov (see map)

-After your check-in at the airport, find Terminál 1 it is a waypoint to get your bus to metro station (underground line) Nádraží Veleslavín.

– Get off the bus at Nádraží Veleslavín station and enter underground line in direction Depo Hostivař and transfer for tram at station Malostranská.

– Exit Malostranská station and get to the ground level. Use the left exit to get to nearby tram station with the same name. Take tram no. 18 to the station Albertov

Faculty

– located several minutes walk from the station. Turn to the perpendicular wide street in between both tram stations and walk to the end of Albertov street. Entrance is from the main street, last building on the right side. In case ask for Albertov building 6.

Pics:

Airport map

Map of transportation services

Transport line from Airport to Faculty

 

Tram- Faculty map

Faculty location: Albertov 6

2) Dining, shops, restaurants

Besides Icebreaker party and coffee breaks, food and drink is not provided by the organizers of the Shortcourse.
Several options are aviable in surrounding area of the Faculty. You can either choose to visit one of the restaurants and bufées or go shopping at nearby supermarket.

Supermarkets and malls

Lidl supermarket: is walking distance from faculty, turn left from Albertov street and follow the tram line. The market is minute away from tram station (by the church 🙂 )
Atrium mall: is located at Karlovo Náměstí: (square, also metro station) small shopping passage with supermarket as well.
Quadrio mall: Large multi level shopping mall right atop Národní třída metro station. 10/15min from faculty.

Restaurants

Best way is to ask around, organizers or othe colleauges can be helpful 🙂

See map:

Map of nearby restaurants

Field trip: SW part of Bohemian Massif- various deposit, cooperation with Baltic Student Chapter

Heritage Stone excursion to the Southwestern part of the Bohemian Massif

Eliška Bršlicová, Marek Tuhý, Rafael Baieta

SGA Student Chapter Prague, Faculty of Sciences, Charles University, Albertov 6, 128 43 Prague 2, Czech Republic; brslicoe@natur.cuni.cz

Photos album link: https://www.zonerama.com/SGA-Prague/Album/3956885

The 2017 autumn field trip organized by SGA Student Chapter Prague took its participants to some world-famous locations, such as Komorní Hůrka, Kössain, Stříbro and Kašperské Hory. Here, we saw the heritage stones of the southwestern region of the Bohemian Massif.

Day 1

We started the day with a visit to the Tis u Blatna quarry (Fig. 1), which is currently mined by GRANIO s.r.o. The special type of granite at this site is locally called “Czech Labradorite” due to its bluish hues that are caused by quartz. Afterwards we visited localities near Horní Slavkov with Sn-W-Mo-Cu-rich quartz veins. First locality Huberův peň used to be mined for Sn and W. The erlan mineralization allows for fairly large crystals of cassiterite to be found alongside wolframite, green and violet apatite, chalcopyrite, topaz, molybdenite and violet fluorite. The second locality in this area, Vysoký kámen, is a greisen-type deposit, where green spheroid chalcosiderite-turquoise chain minerals were formed during decomposition. Finally, we visited the Štenská u Teplé quarry, the only locality in Czech Republic where trachyte is mined.

Fig. 1: Tis u Blatna quarry. Photo by M. Vopat.

Day 2

In the morning, we arrived to Komorní Hůrka (Fig. 2), one of the youngest volcanoes in the Czech Republic, with its age being estimated between 200 000 and 1 million years. Kormorní Hůrka is a stratovolcano, with interchanging eruptions of basaltic lava flows and pyroclastic deposition, both tuff and volcanic bombs can be found at this locality. Afterwards we moved on to Marktredwitz (Fig. 3) where the highway cuts through an assortment of redwitz, from granodioritic to gabbroitic. The next point of interest was Blue Granite in Pfalzbrunnen quarry outside of Kössain. The granite here is being mined for 100 years and is prized for its porphyric structure and fine quality.

Fig. 2: Goethe’s adit for research purposes at Komorní Hůrka. Photo by M. Vopat.

Fig. 3: Feldspars at Marktredwitz. Photo by M. Vopat.

Day 3

We visited Stříbro (Fig. 4), a famous Czech locality with Pb-Zn mineralization and a great history of mining. The first known document referring to the silver mines is from the 12th century. Silver was mined in this area throughout the Medieval ages, then around the 16th century, lead started being mainly mined. The veins contain multiple quartz generations along with galenite, sphalerite, pyrite with marcasite and occasionally chalcopyrite. Then, we moved to a uranium deposit Damětice. It used to be a small mining area. The upper part of the deposit is oxidized and its possible to find uranium micas such as uranocircite, autunite and torbernite while the lower deposit contain primary mineral uraninite. Later, we visited an old marble quarry in Nezdice na Šumavě. The marble in the lower part of the quarry has a beautiful sky-blue color and contains fine needles of wollastonite. We ended our day in Kašperské Hory, an area full of historical gold mines from the 10th and 14th century. The latest geological survey still shows deposits of gold with 5.6 ppm Au.

Fig. 4: Stříbro, heap from Pb-Zn mine. Photo by J. Mysliveček.

Day 4

We arrived early to Malenice (Fig.5), where we observed migmatite and paragneiss boulders containing almandines. Tetragonal trioctahedral and rhombic dodecahedral crystals can be found here or the combination of both. Than we explored the locality Sepekov and we found a group of hercynite spinel-rich rocks and varying content of phlogopite located on the contact of a gneiss-migmatite and tourmaline granite rock bodies. We ended our field trip in Krásná Hora nad Vltavou at an extensive mineralization of gold and antimonic veins stretching throughout the area. We searched around an old rock pile from the mine shaft Emilka consisting of red stained granite with antimony crystals and grains.

Fig. 5: Malenice, paragneiss containing almandines. Photo by D. Brém.