ZAKLAD BO DO PONOVNEGA ODPRTJA MUZEJEV DEAKTIVIRAN.
CACHE IS TEMPORARILY DISABLED, UNTIL MUSEUMS OPEN AGAIN.
(SI) Dva največja rudnika živega srebra na svetu, naša Idrija in Almaden v Španiji, sta zaprta. A njuna dediščina živi in je od 30.6.2012 vpisana na UNESCO Seznam svetovne dediščine!
PRED ZAČETKOM:
Opis tega Geološkega zaklada je dolg. Prosimo, preberite ga in si zapišite naloge za vpis se pred obiskom zaklada!
NALOGE ZA VPIS OBISKA
1. Koliko živega srebra je vsebovala najbogatejša ruda in koliko, najsiromašnejša?
2. Rudniški rovi so v globino razprostranjeni na 15 glavnih nivojih, imenovanih obzorja. I. obzorje je najbližje površini, XV. obzorje pa v najglobljem delu rudnika. Ob zapiranju rudnika so spodnja obzorja zalili z vodo.
2a. Do katerega obzorja je rudnik danes zalit z vodo? Vprašajte vodiča.
2b. Zakaj doslej niso dopustili, da voda zalije rudnik v celoti?
3. V vhodni avli zgradbe Antonijevega rova je v tla vgrajena nekakšna škatla. Kaj je to? Katere barve v "škatli" predstavljajo pot vodenega ogleda?
4. Obiskovalci se po ogledu starejših in novejših jamskih telefonov spustijo v globino po lesenem stopnišču jaška št. 20. Na leseni steni jaška so oznake na črnih tablicah. Ena je na vrhu, pred začetkom spusta, druga na dnu, po koncu spusta (glej sliko 1 pri angleškem besedilu spodaj: Najdite ti dve tablici;).
4a. Kaj pomenita kratici na začetku oznake?
4b. Kaj pomenijo oznake v drugi vrstici?
POMEMBNO!
- Preden vpišete obisk zaklada, pošljite odgovore preko GC profila ali neposredno na e-naslov vane.si.geo@gmail.com. Takoj potem lahko vpišete obisk zaklada na spletu – ne potrebujete dodatnega dovoljenja. Če ste fotografirali, prosimo, priložite kakšno fotografijo.
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- Vpisi, ki vsebujejo odgovor bodo izbrisani!
(ENG) Idrija, Slovenia and Almadén, Spain, two largest Mercury mines in the world, are not in operation any more. But their heritage is alive and since June 30th 2012 inscribed into the UNESCO World Heritage List, as the Heritage of Mercury. This EarthCache offers you to find out more about Mercury.
BEFORE THE BEGINNING:
This EarthCache has a long description! Please, read it and write down logging tasks before visiting the EarthCache site!
LOGGING TASKS
1. How much mercury has the richest ore contained and how much the poorest?
2. Mine tunnels are constructed at 15 main levels. 1st Level is closest to the surface, 15th level is in the deepest part of the mine. Lower parts of the mine have already been flooded at the time of mine-closure works.
2a. Up to which level the mine is flooded today?
2b. Why has not been permitted for water to fill in complete mine until now?
3. In the entry hall of the mine museum building there is a kind of box built into the floor. What is it? Which colors represent the path of the guided tour in this "box"?
4. After explanation about mine communications and seeing mine telephones, visitors descend 22 meters using wooden staircase in the shaft No. 20. There are black plates with some markings pinned to the wooden wall. One is at the top of the staircase and another at the bottom (see photo).
Figure 1: You want to find these two black plates;
4a. What does abbreviation in the beginning of the first line mean?
4b. What is the meaning of marks in the second line?
IMPORTANT!
- Send answers through GC profile or directly to e-mail vane.si.geo@gmail.com
before logging. After that you can log - you don't need an additional permission to log. Please, upload photos if you have taken them.
- Logs without an accompanying e-mail containing correct answers will be encrypted and later deleted!
- Logs containing the answer will be deleted!
slovensko besedilo / Slovenian text
tocke poti in dnevniki / waypoints and logs
Visit our web-site Geološki zakladi / EarthCaches
for a complete list of our EarthCaches and a lot of additional information.
(ENG) MERCURY
Mercury is a heavy, silvery-white metal, the only metal that is liquid at standard conditions for temperature and pressure (air at 0 °C and 10 kPa). As compared to other metals, it is a poor conductor of heat, but a fair conductor of electricity. It has a freezing point at −38,83 °C and boiling point at 356,73 °C. Specific density is more than 13,5 kg/dm3, almost twice as much as iron.
Intriguing because of its silver hue and liquid state at room temperature, elemental mercury was known to the ancient Greeks, Romans, Chinese and Hindus. Each civilization had its own legends about mercury, and it was used as everything from a medicine to a talisman.
Figure 2: A – Position of the mercury in the periodic table of chemical elements, B – spilled droplets of mercury, C – Why does iron ball float at the surface of mercury? Iron has much lower relative desity than mercury;
In alchemy, mercury, sulfur, and salt were supposed to be the Earth's three principle substances. Believing that mercury was at the core of all metals, alchemists supposed that gold, silver, copper, tin, lead and iron were all mixtures of mercury and other substances. European alchemists believed that the correct combination of mercury and other ingredients would yield riches of gold.
With the introduction of amalgamation process to extract silver and gold from ore using mercury, in the midst of the 16th century, mercury became essential in the production of these metals.
Mercury has been used in thermometers, barometers, manometers, sphygmomanometers, float valves, mercury switches, and other devices. In recent decades concerns about the element's toxicity have led to increased replacement of devices containing mercury with other types of instruments. Mercury remains in use in scientific research applications, in amalgam material for dental restoration, and in lighting.
The toxicity of mercury is well-known for centuries. During the Roman Empire, slavery at the Cinnabar mines was used as a terrible punishment for disobedient citizens. This was amounting to a slow, painful death. The first description of industrial poisoning from mercury use is found in 1557. The workers suffered from chronic exposure to inorganic mercury salt, which resulted in restlessness, depression, lack of concentration and the characteristic hand tremor.
IDRIJA ORE DEPOSIT
The Idrija ore deposit is the second largest ore deposit in the world in terms of mercury concentration, being second only to Almadén in Spain. It has also gained international repute and professional significance because of the conditions in which it was formed, its exceptionally rich and unusual ores, geochemical and mineralogical compositions, and the extraordinary transformations into its extremely complex present-day state.
You can read about formation of the ore deposits at this link.
CINNABAR ORES AND NATIVE MERCURY
Idrija's cinnabar ores were formed in two ways, which is unusual for mercury ore deposits. In the first method, ore-bearing solutions trickled across the faults and fractures through older rocks of the Idrija ore deposit – Carboniferous, Permian, Scythian and Anisian rocks. The hot waters dissolved the soluble minerals, primarily calcite (CaCO3), leaving small holes of varying size in the rocks. With the gradually decreasing pressure and the cooling of thermal water from 218° to 160°C, mercury (Hg) and sulphur (S) from the ore-bearing solutions combined to form cinnabar (HgS) or a noncrystallised cinnabar gel. In this way the small holes in the rocks, open faults and fractures were gradually filled with cinnabar (HgS). If there was not enough sulphur present, native mercury was released (shales impregnated with mercury droplets). The ores formed in the described manner are called epigenetic cinnabar ores. These ores are customary and have been documented in other mercury ore deposits around the world.
Figure 3: D - Native mercury in carboniferous shale; E and F – epigenetic cinnabar ore;
Unique and unknown to other Hg deposits are the so-called syngenetic ores, or sedimentary cinnabar ores. Their formation is linked to the outpouring of hydrothermal waters enriched with mercury and sulphur, or directly with the cinnabar gel, into the then existing marshes where various sedimentary rocks, known under the name of Skonca beds, were simultaneously formed. In this second phase of hydrothermal activity, enormous quantities of mercury and sulphur began to flow along the faults. Like the first time, rich epigenetic cinnabar ores were formed in older rocks. Besides, a good part of the cinnabar gels was discharged directly into the marshes, forming rich (up to 78% Hg) sedimentary ores. Due to the small inflow of sulphur, part of the mercury remained in its elemental form, creating ore-bearing deposits with native mercury primarily in the Carboniferous shales (shales impregnated with native mercury droplets), Skonca beds, and partly also in some other rocks.
Figure 4: G to J - Syngenetic cinnabar ore – found in Idrija ore doposit only;
To summarize: epigenetic cinnabar ores have been formed with substitution of older rocks, with filling holes, faults and fractures, on the other hand syngenetic ores are of sedimentary origin and have been formed with slow sedimentation of material at the same time as rocks where they are found today.
IDRIJA MERCURY MINE
The Idrija ore deposit lies directly below the town of Idrija and extends in the direction NW-SE. It is approximately 1500 m long, 300-600 m wide and 450 m deep. Approximately 700 km of shafts have been excavated on 15 levels, where 158 ore bodies were found, of which 141 contain cinnabar (14 ore bodies with mostly syngenetic mineralization and 127 with epigenetic mineralization). Native mercury is predominant in the remaining 17 ore bodies.
According to the legend, mercury was discovered in the last decade of 15th century, by a tub maker who was soaking a wooden vessel in a stream and captured droplets of the metal. Initial mining efforts were not very successful, until miners stumbled upon plentiful lodes in 1508. This prompted a flurry of ownership changes. Soon the mine was acquired by the Habsburgs from Vienna, for whom the mine was an important source of income for years.
The mine was owned and run by the state for centuries. Generous funding and extensive know-how was poured into research and modernization of the mine in order to maximize production. The mine would be the training grounds for numerous scientists of international renown. This ensured that the mine was at the cutting edge of mining technology and engineering in general in Europe, as well as of health, forestry, botany and other sciences.
Apart from the mine itself, Idrija was also home to processing facilities for obtaining pure mercury. Special smelting furnaces of various types were used for turning the mercury ore into metal.
In the time of operation, almost 147.000 tons of mercury or 13% of world’s production has come from Idrija mine.
The gradual closure of the mine has begun in 1988. The program to shutdown the Idrija mine was focused on protecting the town’s centre and the exceptional cultural heritage, located directly above the mine. Reinforcing works were carried out to protect the buildings above the abandoned ore deposit. Groundwater was used to fill the lower parts of the mine. The upper sections of the deposit, where unique cinnabar ores are located in situ, are meanwhile preserved through maintaining the level of water below the IVth gallery and are accessible to visitors.
THE MINE MUSEUM
Anthony’s Main Road, entrance to the mine was constructed in 1500 and is still used as the entrance to the museum part of the mine. Museum manifests the various methods used over the centuries to extract the mercury ore, as well as methods of building supports and the engineering feats, the hoist technology and groundwater pumping systems. Other features include the underground chapel, the Attems’s inclined shaft, and a number of natural and technical attractions unique to this special mine. Another standout feature is the presence of mercury in native form.
EARTHCACHE
Coordinates are set in front of Anthony’s Main Road. Guided tours are offered daily. Opening times and tour timetables are available at this link. The tour lasts about 1 hour and half. You will not regret visiting the mine!
REFERENCES:
1. Heritage of Mercury, Almadén and Idrija, Application Dossier, prepared for a nomination to the UNESCO World Heritage List, Idrija, 2012;
2. Idrija Geopark, Application Dossier for membership in the European Geoparks Network, Idrija, 2011;
3. Anthony’s Main Road, The Mine Museum brochure, Rudnik zivega srebra Idrija, 2009;
4. Structural and Genetic Particularities of the Idrija Mercury Ore Deposit, Mlakar and Drovenik, magazine Geologija 14, Geological Survey, Ljubljana, 1971;
5. Structural history of the Idrija mercury deposit, Ladislav Placer, magazine Geologija 25-1, Geological Survey, Ljubljana, 1982.
Slovensko besedilo
Obiscite naso spletno stran Geološki zakladi / EarthCaches
za seznam vseh nasih Geoloških zakladov in mnogo dodatnih podatkov.
(SI) ŽIVO SREBRO
je težka, srebrno bela kovina, edina ki je tekoča pri standardnih pogojih temperature in pritiska (0 °C in 10 kPa). V primerjavi z drugimi kovinami je slab prevodnik toplote a kar dober prevodnik električnega toka. Tališče ima pri temperaturi −38,83 °C in vrelišče pri 356,73 °C. Specifična gostota je približno 13,5 kg/dm3, ali skoraj dvakrat več kot pri železu.
Zanimivo zaradi svojega srebrnega sijaja in utekočinjenosti pri sobni temperaturi, je bilo živo srebro poznano starim Grkom, Rimljanom, Kitajcem in Hindujcem. Vsaka civilizacija je imela svoje zgodbe o živem srebru in uporabljali so ga za vse namene od zdravila do talismana.
Slika 2: A – Mesto živega srebra v periodnem sistemu elementov, B – razlite kapljice živega srebra, C – železna krogla plava na živem srebru, ker je gostota železa skoraj dvakrat manjša od gostote živega srebra;
V alkimiji so bili živo srebro, žveplo in sol osnovne tri sestavine Zemlje. Alkimisti so verjeli, da je živo srebro v osnovi vsake kovine in torej predpostavljali, da so zlato, srebro, baker, cink, svinec in železo vsi mešanica živega srebra in ostalih snovi. Evropski alkimisti so verjeli, da jim lahko s pravo kombinacijo živega srebra in ostalih sestavin uspe ustvariti kupe zlata.
Sredi 16. stoletja je z iznajdbo amalgamacije in uvajanjem tega procesa v pridobivanje srebra in zlata, živo srebro postalo bistveno za proizvodnjo teh dveh kovin.
Živo srebro je bilo uporabljano v termometrih, barometrih, manometrih, sfigmomanometrih, hidravličnih ventilih, živosrebrnih stikalih in drugih napravah. Zaradi strupenosti živega srebra, so bile v zadnjih desetletjih te naprave v veliki meri nadomeščene z drugimi instrumenti. Živo srebro ostaja v znanstvenih raziskavah, v razsvetljavi (varčne sijalke) in kot amalgamski material v zobozdravstvu.
Strupenost živega srebra je poznana že stoletja. V času rimskega imperija, so suženjsko delo v rudnikih cinobra uporabljali kot strahotno kaznovanje za neubogljive državljane. To je bilo skorajda enačeno s počasnim, bolečim umiranjem. Prvi opisi zastrupitev pri industrijski uporabi živega srebra so nastali leta 1557. Delavci izpostavljeni anorganskim živosrebrnim solem, so postajali nemirni, depresivni, nezbrani, pojavilo se je značilno tresenje rok.
IDRIJSKO RUDIŠČE
Idrijsko rudišče je drugo največje na svetu, takoj za Almadenom v Španiji. Mednarodno znano in strokovno pomembno pa je postalo zaradi pogojev v katerih je nastalo, izjemno bogatih in neobičajnih rud, geokemične in mineraloške sestave ter izjemnih preobrazb, katerih rezultat je današnja zelo zapletena zgradba (struktura).
Več o nastanku rudišča si lahko preberete na tej povezavi.
CINABARIT IN SAMORODNO ŽIVO SREBRO
Idrijska cinabaritna ruda je nastajala na dva načina, kar je nenavadno za živosrebrne rude. Pri prvem načinu se je rudonosna raztopina pretakala po prelomih in razpokah skozi starejše plasti idrijskih kamnin – karbonskih, permskih, skitskih in anizijskih. Vroče vode so raztapljale topljive minerale, predvsem kalcit (CaCO3) in v kamnini za seboj puščale luknjice različnih velikosti. Med postopnim zniževanjem tlaka in ohlajanjem termalnih voda od 218 do 160°C, sta se živo srebro (Hg) in žveplo (S) iz rudonosnih raztopin združevala v mineral cinabarit (HgS) ali pa v nekristaliziran cinabaritni gel. Tako je votlinice v kamninah, odprte prelome in razpoke postopno zapolnil mineral cinabarit (HgS). Ce ni bilo prisotnega dovolj žvepla, je bilo sproščeno samorodno živo srebro, ki ga v skrilavcih prepojenih z živim srebrom najdemo v obliki kapljic. Rude nastale na opisan način so epigenetske cinabaritne rude in so običajne tudi v drugih rudiščih po svetu.
Slika 3: D – Samorodno živo srebro v karbonskih skrilavcih; E in F – epigenetska cinabaritna ruda;
Edinstvene in drugod neznane rude pa so tako imenovane singenetske rude ali sedimentne cinabaritne rude. Njihov nastanek je povezan z izlivanjem hidrotermalnih voda, ki so bile obogatene z živim srebrom in žveplom ali pa že neposredno s cinabaritnim gelom, v takratno močvirje. V močvirju so sočasno nastajale tudi različne močvirske sedimentne kamnine, ki jih poznamo pod imenom Skonca plasti.
V tej drugi fazi hidrotermalnega delovanja so ob prelomih pritekale izjemno velike količine živega srebra in žvepla. Tako kot prvič so v starejših kamninah nastajale bogate epigenetske cinabaritne rude. Dobršen del cinabaritnih gelov pa se je stekal neposredno v močvirje, kjer so se usedale edinstvene, bogate sedimentne rude (z vsebnostjo do 78% živega srebra). Zaradi premajhnega dotoka žvepla je del živega srebra ostal v elementarni obliki in nastalo je orudenje s samorodnim živim srebrom predvsem v karbonskih skrilavcih (samorodni skrilavci), Skonca plasteh in delno se v nekaterih drugih kamninah.
Slika 4: G to J – Singenetska, oziroma sedimentna cinabaritna ruda – najdena samo v idrijskem rudišču;
Ce povzamemo: epigenetske cinabaritne rude so nastale z nadomeščanjem starejših kamnin, zapolnjevanjem prelomov in razpok, singenetske pa so sedimentnega značaja, saj so nastale z usedanjem sočasno s kamninami, v katerih se nahajajo.
RUDNIK ŽIVEGA SREBRA
Idrijsko rudišče lezi neposredno pod mestom in se razteza približno 1500 m v smeri SZ-JV, široko je od 300 do 600 m in 450 m globoko. Na petnajstih obzorjih (nivojih) je bilo izkopano priblizno 700 km rovov! Pri tem so našli 158 rudnih teles, od teh je 141 vsebovalo cinabarit (14 pretežno singenetskega nastanka in 127 epigenetskega). Samorodno živo srebro je prevladovalo v preostalih 17 rudnih telesih.
Po legendi, naj bi živo srebro konec 15. stoletja odkril Škafar, ko je v potoku namakal leseno posodo, v katero so se ujele kapljice nenavadne kovine. Prvi poskusi rudarjenja niso bili zelo uspešni, dokler rudarji v letu 1508 niso naleteli na bogata nahajališča. Po odkritju je lastništvo rudnika hitro prehajal iz rok v roke. Kmalu pa so rudnik pridobili Habsburžani katerim je rudnik prinašal pomemben del prihodkov mnogo desetletij.
Rudnik je bil stoletja v državni lasti. Velike vsote denarja in obsežno tehnološko znanje je bilo usmerjeno v raziskave in posodabljanje rudnika, s ciljem cim večje proizvodnje. Rudnik je postal učni poligon mnogim znanstvenikom mednarodnega slovesa. To je rudniku zagotavljalo vrhunsko tehnologijo rudarjenja in inženirsko znanje, ki sta bila v samem vrhu v evropskem merilu. Podobno je veljalo za zdravstvo, gozdarstvo, botaniko in druge znanosti.
Poleg rudnika so bili v Idriji tudi obrati za pridobivanje živega srebra iz rude. V predelovalnicah so uporabljali posebne žgalne peci različnih vrst, katerih tehnologija se je skozi čas spreminjala.
V času delovanja so v Idriji pridobili skoraj 147.000 ton živega srebra ali 13% vse svetovne proizvodnje.
Postopno zapiranje rudnika so pričeli leta 1988. Program zapiranja je bil usmerjen predvsem v zaščito mestnega središča in izjemne kulturne dediščine, ki se nahaja neposredno nad rudnikom. Za zaščito stavb nad opuščenimi rovi so izvedli ojačitvena dela zgornjih delov rudnika. Z vodo so do danes zapolnili stabilne spodnje predele rudnika. Planirana je postopna potopitev vse do IV. obzorja, zgornje dele rudnika pa bodo ohranili suhe s črpanjem viška vode. Na ta način bodo območja enkratne cinabaritne rude dostopna obiskovalcem in strokovnjakom.
ANTONIJEV ROV
… je vhod v rudnik, ki so ga zgradili leta 1500 in je se danes v uporabi kot vhod v muzejski del rudnika. V muzeju so predstavljene različne metode kopanja rude, kot so se razvijale skozi stoletja, poleg tega pa tudi načini podpiranja rovov in drugi inženirski dosežki, tehnologija dvigovanja, sistemi črpanja podtalnice. Obiskovalci med drugim vidijo tudi podzemno kapelo, Attemsov vpadnik in številne naravne in tehnične zanimivosti, ki so unikatne za ta dragoceni rudnik. Na ogled je se ena izjemna posebnost: samorodno živo srebro!
GEOLOŠKI ZAKLAD
Koordinate so postavljene k vhodu v Antonijev rov, oziroma vhodu v objekt Šelštev, v katerem se Antonijev rov prične. Vodeni ogledi so na voljo vsak dan. Urnik ogledov in cenik sta na tej povezavi. Ogled rudnika traja približno eno uro in pol. Oglejte si rudnik, ne bo vam zal!
VIRI:
1. Dediščina živega srebra, Almadén in Idrija, kandidatura za vključitev na UNESCO seznam svetovne dediščine, Idrija, 2012;
2. Geopark Idrija, kandidatura za vključitev v evropsko mrežo geoparkov, Idrija, 2011;
3. Antonijev rov, brošura muzejskega dela rudnika, Rudnik živega srebra Idrija, 2009;
4. Strukturne in genetske posebnosti idrijskega rudišča, Mlakar in Drovenik, Geologija 14, Geološki zavod, Ljubljana, 1971;
5. Tektonski razvoj idrijskega rudišča, Ladislav Placer, Geologija 25-1, Geološki zavod, Ljubljana, 1982.
tocke poti in dnevniki / waypoints and logs