geologicalsurveyoffinland pahtavuoma -...

Mineral Deposit Report OF 21 29.4.2020Geological Survey of Finland

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PahtavuomaOccurence type: deposit

Commodity Rank Totalmeasure

Total production Total resource Importance

zinc 1 143025.6 t 0 t 143025.6 t Mediumsized deposit

copper 2 67992.07 t 3156.67 t 64835.4 t Small depositcobalt 2 2584.8 t 0 t 2584.8 t Medium

sized depositlead 3 16370.4 t 0 t 16370.4 t Small depositnickel 3 4738.8 t 0 t 4738.8 t Small deposituranium 3 646.2 t 0 t 646.2 t Small depositsilver 3 228.87 t 5.31 t 223.56 t Small depositmolybdenum 4 33.6 t 0 t 33.6 t Occurrenceiron 5 1628424 t 0 t 1628424 t Small depositsulphur 5 521698.8 t 0 t 521698.8 t Medium

sized deposit

Easting EUREF: 384095.198 Easting YKJ: 3384221Northing EUREF: 7523052.779 Northing YKJ: 7526196

Discovery year: 1971Discovered by: Outokumpu OyProvince: Kittilä (Au, Cu)District: Sirkka (Cu, Au, Ni, Co)Comments: Sulphide dissemination detected in outcrop during regional explorationReferences: 3, 7, 9, 13, 17, 18, 19, 21, 22, 25, 28, 30, 33, 34

Mineral deposit type

Group:Metallogenic depositMain type: VMS (mixed hydrothermal)Comments:Mineralisation is a product of submarine tholeiitic volcanism and related hydrothermalsystem in a sediment-dominated rift basin. Magmatism and syngenetic mineralisation took place in asubmerged rift, precipitation of ore metals and S at sea floor. Sulphur of the ore was derived fromsulphates sea-water or marine-sediment origin.References: 1, 5, 6, 10, 11, 23, 26

Dimension

Expression: exposed Area (ha): NAForm: concordant Dip azim: 22Shape: NA Dip: 70Length (m): NA Plunge azim: NAWidth (m): NA Plunge dip: NAThickness (m): NA Orientation method: NADepth (m): NADimension comments: Six Zn, four Cu, and three U ore bodies; the Cu and U ore bodies are separatefrom the Zn ones; all have a E-W trend and a dip of 60-80° to the N. The Cu ore bodies are sited alongsedimentary-volcanic contact zone.


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Holder history

Current holder: Outokumpu Mining OyYears: 1977Holding type:Mining concession (old law)

Previous holders:

Company Years Holding type CommentsOutokumpu Oy 1970 NA NA


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EXPLORATION ACTIVITY

Geological Survey of Finland

Years Activity type Geologist Exploration result Ref2008-2008 detailed geophysics NA geophysical anomaly 10

Graphite-rich units, which host all ore, give a strong response on electric methods.

2004-2004 regional geophysics NA key geological features 2, 4, 29, 31Low-altitude airborne magnetic, electromagnetic and radiometric survey

University of Turku

Years Activity type Geologist Exploration result Ref1984-1986 detailed geology Seppo Roos key geological features 1, 3, 25, 26, 34

Outokumpu Oy

Years Activity type Geologist Exploration result Ref1974-1976 mining pilot Osmo Inkinen mineral reserve defined 10, 14, 17

1971-1974 core drilling Osmo Inkinen mineral resource defined 10Core drilling (reconnaissance drilling): 121 diamond-drill holes.


Years Activity type Geologist Exploration result Ref1970-1985 regional

geochemistryHeikki Hirvas geochemical anomaly 4, 5, 6, 7, 8, 20, 29,

31, 33Till geochemical survey, regional till stratigraphy and glacial erratic boulder survey. Distinct As, Cu and Znanomalies in till. U-rich boulder trains start from the Pahtavuoma U lodes.

Outokumpu Oy

Years Activity type Geologist Exploration result Ref1962-1985 regional

geochemistryNA geophysical anomaly 16

Numerous Cu anomalies detected in stream sediment surveys

1961-1985 detailed geology Osmo Inkinen, UllaLatvalahti, Markku Mäkelä

mineral occurrences 2, 10, 12, 14, 15, 16,17, 18, 21, 22, 24, 32

Geology, ore mineralogy, S-isotope investigations; ore body extents


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1961-1985 regional geophysics Osmo Inkinen geophysical anomaly 10, 12, 14, 15, 20,23, 32

1961-1985 detailed geophysics Osmo Inkinen geophysical anomaly 10, 12Graphite-rich units, which host all ore, give a strong response on electric methods.


Years Activity type Geologist Exploration result Ref1954-2000 regional geology Pentti Rastas, Matti

Lehtonen, Irmeli Mänttäri,Pentti Hölttä

key geological features 2, 9, 19, 20, 23, 29,31

Regional bedrock mapping, stratigraphy assessment, radiometric dating and regional metamorphicinvestigations


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RESOURCES AND RESERVES

Most recent

Type: Company: Year: Date: Calc Method: Reference:Resource Outokumpu Oy 1976 NA Non-compliant resource

estimate16

Category: Poorly estimated mineral resource, poorly documentedTonnage: 4.4 Mtcopper 1.04 %zinc 0.12 %lead 0.02 %nickel 0.03 %cobalt 0.02 %silver 23 ppmiron 7.53 %sulphur 2.34 %Cutoff: copper 0.6 %Comments: Orebodies: A, Ulla I, Ulla II, Central, WesternCategory: Poorly estimated mineral resource, poorly documentedTonnage: 21.54 Mtzinc 0.664 %cobalt 0.012 %copper 0.301 %silver 10.379 ppmnickel 0.022 %lead 0.076 %uranium 0.003 %molybdenum 1.56 ppmiron 7.56 %sulphur 2.422 %Cutoff: NACategory: Poorly estimated mineral resource, poorly documentedTonnage: 0.14 Mturanium 0.39 %zinc 0.08 %copper 0.24 %sulphur 2.82 %lead 0.09 %nickel 0.02 %cobalt 0.01 %silver 24 ppmmolybdenum 240 ppmCutoff: NACategory: Poorly estimated mineral resource, poorly documentedTonnage: 17 Mtzinc 0.81 %copper 0.11 %lead 0.09 %nickel 0.02 %cobalt 0.01 %silver 7 ppmiron 7.63 %sulphur 2.44 %


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Cutoff: NA

Previous calculations

Type: Company: Year: Date: Calc Method: Reference:Resource NA 1979 NA Non-compliant resource

estimate10

Comments: U-I, U-II and U-III. The lodes are thin, subvertical sets of veins. Thelengths of the lodes are 100 m.Category: NATonnage: 0.3 Mturanium 0.19 %Cutoff: uranium 0.03 %


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MINING

Pahtavuoma

Easting EUREF: 384095.198Northing EUREF: 7523052.779Status: ClosedOperating years: 1974-1993Years in production: 6Total ore mined: 295239 tReferences: 27

Total production:Product Product measurecopper 3156.67 tsilver 5.31 t

Other materials:Material type Material measurewaste from mineral metalliferousexcavation

333970 t

Mining activity:Year Ore mined Ore

processedActivity type Production Other material

1993 261208 t 261208 t open-pit andunderground mining

copper 2821.04 tsilver 4701.74 kg

waste from mineralmetalliferous excavation230519 t

1992 0 t 0 t NAwaste from mineralmetalliferous excavation28501 t

1989 13231 t 13231 t NAcopper 133.63 tsilver 238.15 kg

wastes from mineralexcavation 0 t

1976 2300 t 2000 t NAcopper 20.2 tsilver 37 kg


1975 18500 t 18000 t NAcopper 181.8 tsilver 333 kg


1974 0 t 0 t NAwaste from mineralmetalliferous excavation25000 t


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GEOLOGYHost rock: Skarn, Black schist, Mica schist, GreywackeWall rock:Mafic volcanic rock

Skarn (Host rock)

Rock type: Host rockProportion: presentGrain size: NAColor: NAReferences: 10, 14, 34Comments: Carbonate- and calc-silicate-bearing albite-amphibole schist, cut by veins of carbonate,carbonate + amphibole & carbonate + pyrrhotite. Sphalerite, magnetite & uraninite occur as veinletsor nests, uraninite as streaks or in the cement of microbreccia.

Ore minerals:Mineral Proportion Mineral textureArsenopyrite minorChalcopyrite minorGalena minorMolybdenite majorPyrrhotite minorSilver minorSphalerite minorUraninite major Stringer, Colloidal

Anhedral to colloidal veinlets in veins with silicates and fine-grainedmolybdenite. Fine-grained uraninite occurs as thin veins inassociation with pigmentous graphite and hematite. Intergrowthsof uraninite, thucolite, pyrrhotite and molybdenite. U-Mo type:subrounded uraninite < 0,2 mm in diameter; in places colloidal withmicroflakes of molybdenite. U-Zn type: ore minerals as veins orclusters, uraninite grains as stripes or as in matrix of microbreccia.

Other minerals:Mineral Proportion Mineral textureAmphibole present

BrownCalcite presentQuartz present

StructuresShearedFractured

Metamorphic description:

Type: Facies: Degree: Relation tomineralization:

Min P- Max P(kbar)

MIn T- Max T(°C)

Regional greenschistmetamorphic facies

low metamorphicgrade

NA


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Geological age:

Geological era: Max age - Minage(Ma):

Inferred age (Ma): Age of mineralization:

Paleoproterozoic (2500-1600Ma)

1600-2500 N

Black schist (Host rock)

Rock type: Host rockProportion:majorGrain size: NAColor: NAReferences: 1, 10, 18, 23, 32, 34, 35Comments: Six Zn lodes, four Cu lodes, and three U lodes; the Cu and U lodes are separate from theZn lodes.

Ore minerals:Mineral Proportion Mineral textureArgentopentlandite minorArsenopyrite minorChalcopyrite minorCobaltite minorCobaltpentlandite minorGalena minorGersdorffite minorGold minorGraphite minorIlmenite minorMackinawite minorMagnetite minorMarcasite minorMolybdenite minorNickeline minorPyrite minorPyrrhotite major Breccia, DisseminationSphalerite major Breccia, Dissemination

Grain size of sphalerite is in veins 0.2-0.5 mm and 0.05-0.1 mm indissemination.

Tucekite minorUraninite minor

Other minerals:Mineral Proportion Mineral textureAnkerite presentCalcite presentQuartz present

StructuresBreccia

TexturesBanded


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Alteration: Distribution: Degree: Relation to mineralization:albitic alteration Disseminated Strong Postscapolitisation Disseminated Strong Post



Min P- Max P(kbar)

MIn T- Max T(°C)



NA 4-6.7 360-500

Comments: Biotite-albite-quartz-graphite ± garnet, actinolite, tourmaline.

Geological age:




1600-2500 N

Mica schist (Host rock)

Rock type: Host rockProportion:majorGrain size: NAColor: NAReferences: 1, 10, 18, 23, 34Comments: The deposit is in a sedimentary- and pyroclastic-dominated subsequence, right abovemafic metavolcanic rocks.



Min P- Max P(kbar)

MIn T- Max T(°C)



NA 4-6.7 360-500

Comments: Quartz-albite-biotite ± garnet, actinolite, scapolite, tourmaline.

Geological age:




1600-2500 N

Greywacke (Host rock)

Rock type: Host rockProportion:minorGrain size: NAColor: NAReferences: 1, 10, 18, 23, 32, 34, 35Comments: The deposit is in a sedimentary- and pyroclastic-dominated subsequence, right abovemafic metavolcanic rocks.


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Min P- Max P(kbar)

MIn T- Max T(°C)



NA 4-6.7 360-500

Comments: Quartz-albite-biotite ± garnet, actinolite, scapolite, tourmaline.

Geological age:




1600-2500 N

Mafic volcanic rock (Wall rock)

Rock type:Wall rockProportion:majorReferences: 1, 3, 10, 14, 16, 17, 18, 25, 26, 34Comments:Metabasalts of, probably, both lava and pyroclastic origin



Min P- Max P(kbar)

MIn T- Max T(°C)



Comments: albite-actinolite-biotite-ilmenite ± scapolite, quartz, titanite, carbonate + locally, relict cpx

Figures


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Regional geology:

Structure:


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Local geology:

Plan view:


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Regional geology:


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Ore outcrop:

Ore outcrop:


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Structure:


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Lithology:


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REFERENCES1. Aatos, S. 1992. Geokemiallisen muuttumisindeksin soveltaminen metamorfoituneiden vulkaanis-sedimenttisten sinkkiesiintymien sivukiviin. MSc thesis. Department of Geology, University of Turku.114 p. (in Finnish)

2. Anon. 1981. IUREP (International Uranium Resources Evaluation Project) orientation phase missionreport: Finland. OECD Nuclear Energy Agency. 104 p.

3. Eilu, P. 1987. Muuttumisilmiöiden keskinäistä vertailua. In: H. Papunen (ed.) Lapin vulkaniittientutkimusprojekti. Loppuraportti. Department of Geology, University of Turku Report. 165-170. (inFinnish)http://tupa.gtk.fi/raportti/arkisto/71_2014.pdf

4. Hirvas, H. & Mäkinen, K. 1984. Raportti malminetsintää palvelevista maaperätutkimuksista KittilänPahtavuoman alueella 05 - 14.06.1984. 5 p. Geological Survey of Finland, unpublished report P13.2.059. (in Finnish)http://tupa.gtk.fi/raportti/arkisto/p13_2_059.pdf

5. Hirvas, H. & Mäkinen, K. 1984. Raportti malminetsintää palvelevista maaperätutkimuksista KittilänPahtavuoman alueella 06-17.06.1983. 6 p. Geological Survey of Finland, unpublished report P13.2.048. (in Finnish)http://tupa.gtk.fi/raportti/arkisto/p13_2_048.pdf

6. Hirvas, H. & Mäkinen, K. 1985. Uranium boulder tracing at Pahtavuoma, Kittilä. In: Saarnisto, M.(ed.) INQUA till symposium Finland 1985 : excursion guide : field workshop August 20-29, 1985.Espoo: Geological Survey of Finland, 109-111.

7. Hirvas, H. & Mäkinen, K. 1989. Tracing of uranium-rich boulders at Pahtavuoma, northern Finland.In: DiLabio, R. N. W. & Coker, W. B. (eds.) Drift Prospecting. Geological Survey of Canada. Paper 89-20, 7-12.

8. Hirvas, H. & Mäkinen, K. 1994. Reperage de blocs glaciaires riches en uranium a Pahtavuoma, dansle nord de la Finlande. In: DiLabio, R. N. W & Coker, W. B. (eds.) La prospection glacio-sedimentaire.Geological Survey of Canada. Paper 89-20, 9-14.

9. Hölttä, P. & Karhu, J. 2001. Oxygen and carbon isotope compositions of carbonates in thealteration zones of orogenic gold deposits in central Finninsh Lapland. Geological Survey of FinlandSpecial Paper 31, 25-29.http://tupa.gtk.fi/julkaisu/specialpaper/sp_031_pages_025_029.pdf

10. Inkinen, O. 1979. Copper, zinc, and uranium occurrences at Pahtavuoma in the Kittilä greenstonecomplex, northern Finland. Economic Geology 74 (5), 1153-1165.

11. Ketola, M., Piiroinen, E. & Sarikkola, R. 1975. On feasibility of airborne radiometric surveys foruranium exploration in Finland. Tiivistelmä: Aeroradiometristen mittausten käyttömahdollisuuksistauraaninetsinnässä Suomessa. Geological Survey of Finland, Report of Investigation 7. 43 p.http://tupa.gtk.fi/julkaisu/tutkimusraportti/tr_007.pdf

12. Ketola, M. 1979. On the application of geophysics in the indirect exploration for copper sulphideores in Finland. In: Hood, P.J. (ed.) Geophysics and Geochemistry in the Search for Metallic Ores.Geological Survey of Canada. Economic Geology Report 31, 665-684.

13. Kokkola, M. & Korkalo, T. 1976. Pahtavuoma: copper in stream sediment and till. Journal ofGeochemical Exploration 5, 280-287.

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14. Korkalo, T. 1977. The Pahtavuoma Cu-mineralisation. Studies conducted in the area. In:Prospecting in areas of glaciated terrain, August 1977, Finland. Excursion Guide, 14-17.

15. Korkalo, T. 1979. Kittilän Pahtavuoman uraaniesiintymä. In: Parkkinen, M. (ed.) Uraaniraaka-ainesymposiumi (1979). Vuorimiesyhdistys. Sarja B 27, 80-87. (in Finnish)

16. Korkalo, T. 2006. Gold and copper deposits in Central Lapland, northern Finland, with specialreference to their exploration and exploitation. Acta Univ. Oulensis, A Scientiae Rerum Naturalium461. 122 p.http://herkules.oulu.fi/isbn951428108X/isbn951428108X.pdf

17. Korvuo, E. 1997. The Saattopora gold ore and the Pahtavuoma Cu-Zn-U occurrences in the Kittiläregion, northern Finland. In: E. Korkiakoski & P. Sorjonen-Ward (eds) Ore deposits of Lapland innorthern Finland and Sweden. Geological Survey of Finland, Guide 43, 21-25.http://tupa.gtk.fi/julkaisu/opas/op_043_pages_021_025.pdf

18. Latvalahti, U. 1974. Kittilän Pahtavuoman malmigeologiasta. MSc thesis. Department of Geology,University of Turku. 90 p. (in Finnish)

19. Lehtonen, M., Airo, M.-L., Eilu, P., Hanski, E., Kortelainen, V., Lanne, E., Manninen, T., Rastas, P.,Räsänen, J. & Virransalo, P. 1998. Kittilän vihreäkivialueen geologia: Lapin vulkaniittiprojektinraportti. Summary: The stratigraphy, petrology and geochemistry of the Kittilä greenstone area,northern Finland: a report of the Lapland Volcanite Project. Geological Survey of Finland, Report ofInvestigation 140. 144 p.http://tupa.gtk.fi/julkaisu/tutkimusraportti/tr_140.pdf

20. Lehtonen, M., Hanski, E., Kortelainen, V., Lanne, E., Manninen, T., Rastas, P., Räsänen, J. &Väänänen, J. 1998. Stratigraphical map of the Kittilä greenstone area. Espoo: Geological Survey ofFinland.

21.Mäkelä, M. & Tammenmaa, J. 1978. Lapin rikki-isotooppitutkimus vuosina 1974-1976. Summary:Sulfur isotope studies in Finnish Lapland, 1974-1976. Geological Survey of Finland, Report ofInvestigation 24. 64 p.1.http://tupa.gtk.fi/julkaisu/tutkimusraportti/tr_024.pdf

22.Mäkelä, M. 1977. Sulfur isotope stratigraphy in some Finnish ore deposits. GeologiskaFöreningens i Stockholm Förhandlingar 99, 163-171.

23.Mänttäri, I. 1995. Lead isotope characteristics of epigenetic gold mineralization in thePalaeoproterozoic Lapland greenstone belt, northern Finland. Geological Survey of Finland, Bulletin381. 70 p.http://tupa.gtk.fi/julkaisu/bulletin/bt_381.pdf

24. OECD 1999. NEA/IAEA Report, Environmental activities in uranium mining and milling. Finland p.88-89.http://tupa.gtk.fi/karttasovellus/mdae/references/169_Luhti/169_766-environmental-activities.pdf

25. Papunen, H. (ed.) 1990. Sinkkiprojektin loppuraportti. University of Turku, Institute of Geologyand Mineralogy, Publication 22. 143 p. (in Finnish)

26. Papunen, H. 1987. Pahtavuoman geokemiasta ja malmimallista. In: Papunen, H. (ed.) Lapinvulkaniittien tutkimusprojekti. Loppuraportti. Department of Geology, University of Turku Report. 20-46. (in Finnish).

27. Puustinen, K. 1995. Suomen malmikaivokset vuosina 1530-1994. Geological Survey of Finland,Report M10.1/-95/1. 96 p. (in Finnish)http://tupa.gtk.fi/raportti/arkisto/m10_1_95_1.pdf

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28. Pääkkönen, K. 1988. Tutkimustyöselostus Kittilän ja Muonion kunnissa valtausalueilla Kolvakero1-3, kaiv.rek. n:o 3315 sekä Laavivuoma 1-2 ja Kolvakero 4, kaiv.rek. n:o 3572 suor.malmitutkimuksista vv. 1982-1985. 6 p. Geological Survey of Finland, unpublished report M06/2741/-88/1/60. (in Finnish)http://tupa.gtk.fi/raportti/valtaus/m06_2741_88_1_60.pdf

29. Pääkkönen, K. 1988. Uraanimalmitutkimukset Pahtavuoman - Kolvakeron alueella Kittilässä jaMuoniossa vuosina 1982 - 1985. 34 p. Geological Survey of Finland, unpublished report M19/2741/-88/1/60. (in Finnish)http://tupa.gtk.fi/raportti/arkisto/m19_2741_88_1_60.pdf

30. Pääkkönen, K. 1988. Uraanimalmitutkimukset Pahtavuoman-Kolvakeron alueella Kittilässä jaMuoniossa vuosina 1982-1985. Geological Survey of Finland, Report M19/2741/-88/1/60. 34 p. (inFinnish)http://tupa.gtk.fi/raportti/arkisto/m19_2741_88_1_60.pdf

31. Pääkkönen, K. 1988a. Tutkimustyöselostus Kittilän ja Muonion kunnissa valtausalueilla Kolvakero1-3, kaiv.rek. n:o 3315 sekä Laavivuoma 1-2 ja Kolvakero 4, kaiv.rek. n:o 3572 suor.malmitutkimuksista vv. 1982-1985. Geological Survey of Finland, Report M06/2741/-88/1/60. 6 p. (inFinnish)http://tupa.gtk.fi/raportti/valtaus/m06_2741_88_1_60.pdf

32. Rehtijärvi, P. & Lindqvist, K. 1978. Uraani ja torium eräissä uraaniesiintymien näytteissä:tiivistelmä menetelmistä ja tutkimustuloksista. Helsingin yliopisto. Geologian laitos. Tiedonanto 7. 86p. (in Finnish)

33. Ristiluoma, S. & Mattila, P. 1972. Pohjois-Suomen malminetsintää palveleva maaperätutkimus. 3.Pahtavuoman osaprojekti. Geological Survey of Finland, Report P 13.2.001. 8 p. (in Finnish)http://tupa.gtk.fi/raportti/arkisto/p13_2_001.pdf

34. Roos, S. 1987. Pahtavuoma. In: Papunen, H. (ed.) Lapin vulkaniittien tutkimusprojekti.Loppuraportti. Department of Geology, University of Turku Report. 14-19. (in Finnish).http://tupa.gtk.fi/raportti/arkisto/71_2014.pdf

35. Törnroos, R. 1982. Sphalerite geobarometry of some metamorphosed sulphide ore deposits inFinland. Geological Survey of Finland, Bulletin 323. 42 p.http://tupa.gtk.fi/julkaisu/bulletin/bt_323.pdf

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