GIS / GEODE
@ brgm
Vihanti
FINLAND
FIN-00004
Pb 101 160, Class B
Zn 1 438 720, Class B
Ag 703, Class C
Au 14, Class C
Cu 134 880, Class C
Py
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Long (E): 25.135 |
Lat (N): 64.405 |
Province: Central Finland/Ostrobothnia |
Status: Old industrial mine, exhausted deposit
Company: Outokumpu Mining Oy
GEODE ID: FENNOSCANDIAN 4
Comment:
Three ore types: Zn-Cu-Pb; pyrite-Cu and U-P, of which the Zn ore was the most important; U-P mineralization was not exploited
metamorphosed volcanic-hosted massive sulphide deposit
massive sulphides, disseminated sulphides
Age of mineralization: 1.92 Ga (Palaeoproterozoic) – Model age from galena: 2.12 or 2.07 Ga; minimum age from cross cutting microcline dyke 1.86 Ga; ore galena Pb-Pb method: 1.918 or 1.925 Ga
Ore minerals: Zn-ore: sphalerite, chalcopyrite, galena, pyrrhotite, pyrite; baryte common gangue, pyrite-Cu ore: pyrite, chalcopyrite
Ore mineralogy for Au: Native and electrum; inclusions in sulphides
Alteration: sericitization in pyrite ore, Mg-skarn in carbonate rocks
Age of host rocks: Palaeoproterozoic; 1.93–1.96 Ga zircon ages of sedimentary-volcanic host rocks
Nature of host rocks: The Vihanti Formation, Zn-ore: calcareous rocks (dolomites and calc-silicate rocks)± felsic volcanics, cordierite-bearing metasomatites, black schists; pyrite-Cu ore: felsic volcanics
Host rock mineralogy: In Zn deposit: Dolomite and calcite, diopside, tremolite; in Cu-pyrite deposits: sericite, feldspars and quartz, cordierite, chlorite, garnet
Mining: underground mining, cut and fill, abandoned
Substances: Zn, Cu, Pb, pyrite, Ag
Total production 1954-1992: 28.1 Mt @5.12 % Zn, 0.48 % Cu, 0.36 % Pb, 25 g/t Ag, 0.49 g/t Au (Kousa et al. 1997)
Geology
Mineralization
Ore age Palaeoproterozoic 1.92 Ga
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Ore mineralogy |
Hydrothermal alteration |
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Sphalerite Chalcopyrite Galena Pyrrhotite Pyrite |
Sericitization Skarn formation |
Host rocks
Host rock age Palaeoproterozoic 1.93–1.96 Ga
Host rock mineralogy
Barite
Diopside
Tremolite
Barite
Quartz
Dolomite
(rutile, graphite, tourmaline)
Host rock lithology
Undifferentiated calc-silicate rock
Dolomite, dolostone
Saturated acidic volcanic rock s.l.
Metasomatic rock
Cordierite-anthophyllite rock
Graphitic shale
Hostrock formation names
The Vihanti Formation
Economy
Underground mining
Zn Zinc (metal)
Primary sulphide ore (complex-sulphides, arsenides, sulphosalts, etc.)
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Past; 1 438 720 |
Production average 5% |
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Cu Copper (metal)
Ore of indeterminate nature
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Past; 134 880 |
Production average |
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Pb Lead (metal)
Primary sulphide ore (complex-sulphides, arsenides, sulphosalts, etc.)
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Past; 101 160 |
Production average |
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Py Pyrite (FeS2)
Ag Silver (metal)
Ore of indeterminate nature
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Past; 703 |
Production average 25 g/t |
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Au Gold (metal)
Ore – native and electrum; inclusions in sulphides
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Past; 14 |
Production average |
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Geological bibliography
Kousa, Jukka; Luukas, Jouni; Mäki, Timo; Ekdahl, Elias; Pelkonen, Kalevi; Papunen, Heikki; Isomäki, Olli-Pekka; Penttilä, Vesa-Jussi; Nurmi, Pekka 1997. Geology and mineral deposits of the central Ostrobothnia. In: Weihed, P. & Mäki, T. (eds.) Research and exploration - where do they meet? 4th Biennial SGA Meeting, August 11–13, 1997, Turku, Finland.
Excursion guidebook A2: volcanic hosted massive sulphide and gold deposits in the Skellefte district, Sweden and western Finland. Geologian tutkimuskeskus. Opas 41: 43–67.
Laznicka, Peter 1993. Vihanti Zn-Cu-Pb deposit, W-C Finland. In: Precambrian empirical metallogeny: Precambrian lithologic associations and metallic ores. Vol. 2 of empirical metallogeny. Part a. Amsterdam: Elsevier, 380–382.
Mikkola, Aimo K.; Rouhunkoski, Pentti 1980. The copper deposits and their metallogeny in southern Finland. In: Jankovic, S. & Sillitoe, R. H. (eds.) European Copper Deposits : proceedings of an International Symposium held at Bor, Yugoslavia, 18–22 September 1979. Belgrade: Belgrade University. Faculty of Mining and Geology, 180–187.
Rehtijärvi, Pentti; Äikäs, Olli; Mäkelä, Markku 1979. A middle Precambrian uranium- and apatite-bearing horizon associated with the Vihanti zinc ore deposit, western Finland. Economic Geology 74: 1102–1117.
Rouhunkoski, P. 1968.On the geology and geochemistry of the Vihanti zinc ore deposit. Bull. Comm. geol. Finlande 236: 121 p.
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Compiler: L. Rajavuori |
Date: 20-08-01 |
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Checked by: H. Papunen |
Check date: 31-12-01 |
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Administrator: D. Blundell |
Event date: 16-11-01 |
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