Name 1
ROCKS OF THE IDRIJA ORE DEPOSIT
Name 2
/
ID number
002.7.Idrija
Manager / Administrator
Idrija Mercury Heritage Management Centre, Bazoviška 2, SI-5280 Idrija
Ownership
Public
Owner
Republic of Slovenia
Local / Original ID Number
/
Type of Object
Ore deposit
Description
Short description
The collection has 108 different non-mineralised rocks of Idrija ore deposit of various forms and sizes. Different sedimentary structures and textures and many deformations can be observed in the rocks. In individual samples we can also find fossil remains (e.g. plant and mussels prints), which were rare in Idrija ore deposit. In carbon mudstone we find typical lenses of pyrite. Some pieces of rock are unique, such as specimens of kaolinite rocks and Skonca beds. Some samples were transected and polished. In the short description of samples, the sedimentary-petrographic characteristics are presented, their creation environments and their structural position is explained.
Measures
108 samples of different dimensions.
Materials
Rocks - claystone, sandstone, mudstone, siltstone, marl, dolomite, limestone, sandstone, conglomerate, breccia, kaolinite rock, tuffite sandstone, tuffite, chert, lenses of pyrite, plant residues.
Dating
The rock samples are from the carbon, Permian period and Early and Mid-Triassic (Scythian, Anisian, Ladinian).
Author / Producer
/
Picture attachments
Original use
The lithological development of the rocks in the Idrija ore deposit was the same as elsewhere in Idrija right up until the Anisian period. After the creation of the Idrija Mid-Triassic tectonic rift, special rocks started to deposit, which were found only in the ore deposit and are a great distinctive feature. They are primarily kaolinite rocks, formed in wetlands, which were constantly covered by slope alluvial cones and Skonca beds – bituminous shales, siltstone and sandstone, which were deposited in wetlands rich with plants. In tertiary tectonic processes, a block of mineralised rock was in an inverse position, therefore, the older carbon rock are nowadays above the younger layers. Due to the exceptionality of creation and development of the Idrija ore deposit, many samples are unique.
Present use
The ore samples are being preserved, secured and presented as important natural heritage of Idrija ore deposit with exceptional universal values. The collection wraps up the discoveries of several generations of geologists on the creation and development of the Idrija ore deposit, which has represented a special challenge for several researchers. It represents a unique soil “archive”, as all the displayed rocks were excavated in Idrija ore deposit and also stored. The larger part of the collection is displayed and available to researchers in the CUDHg administrative premises within the Francis’ shaft. The described specimens are mostly presented in display cases and the rest of them are stored in the drawers under the display cases. Some samples in the drawers can be used for temporary exhibitions and for other types of mercury heritage promotions.
Original location
Rock samples are from different ore bodies from the I to the XIV level of the Idrija Mine.
Present location
CUDHg (Mining Geological Collection), Bazoviška 2, SI-5280 Idrija
STATE OF CONSERVATION
History of conservation:
The rocks are appropriately preserved. Due to the decay of clay minerals, some samples were protected with vacuum impregnation in 2017. Security of the premises is taken care of.
Present state
good
Necessary activities:
Regular seasonal maintenance.
DOCUMENTATION
Addresses / collections / links etc. where further in-depth information is accessible:
- CUDHg Inventory Book;
- Čar, Jože. Rudniška geološka zbirka: Seznam in opis vzorcev. Mercury Mine Idrija, 2003, p. 1‒122, [material is kept in the CUDHg archive];
- Čar, Jože. Razvoj srednjetriasnih sedimentov v idrijskem rudišču: doctoral thesis. The Faculty of Natural Sciences and Engineering in Ljubljana, 1985;
- Čar, Jože. Okolje nastanka anizijskega dolomita nad srednjetriasno erozijsko diskordanco v idrijskem rudišču. Rudarsko-metalurški zbornik, 36/2, 1989, p. 395‒407;
- Čar, Jože, Gregorič, Vera, Ogorelec, Bojan and Saša Orehek. Sedimentološki razvoj skitskih plasti v idrijskem rudišču. Rudarsko-metalurški zbornik, 27/1, 1980, p. 3–20;
- Drovenik, Matija, Čar, Jože, Strmole, Dragica. Langobardske kaolinitne usedline v idrijskem rudišču. Geologija, 18, 1975, p. 107–155;
- Mlakar, Ivan. Primerjava spodnje in zgornje zgradbe idrijskega rudišča. Geologija, 10, 1967, p. 87–126.
- Čar, Jože. Rudniška geološka zbirka: Seznam in opis vzorcev. Mercury Mine Idrija, 2003, p. 1‒122, [material is kept in the CUDHg archive];
- Čar, Jože. Razvoj srednjetriasnih sedimentov v idrijskem rudišču: doctoral thesis. The Faculty of Natural Sciences and Engineering in Ljubljana, 1985;
- Čar, Jože. Okolje nastanka anizijskega dolomita nad srednjetriasno erozijsko diskordanco v idrijskem rudišču. Rudarsko-metalurški zbornik, 36/2, 1989, p. 395‒407;
- Čar, Jože, Gregorič, Vera, Ogorelec, Bojan and Saša Orehek. Sedimentološki razvoj skitskih plasti v idrijskem rudišču. Rudarsko-metalurški zbornik, 27/1, 1980, p. 3–20;
- Drovenik, Matija, Čar, Jože, Strmole, Dragica. Langobardske kaolinitne usedline v idrijskem rudišču. Geologija, 18, 1975, p. 107–155;
- Mlakar, Ivan. Primerjava spodnje in zgornje zgradbe idrijskega rudišča. Geologija, 10, 1967, p. 87–126.
Submitted
Mestni muzej Idrija
Submitted by
Miha Kosmač
Date Submitted
27. 2. 2018
Date Edited
Never