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Modified: 13.08.2009

Kuikkapuro - Gold Database

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Name Kuikkapuro DATA UPDATED 18.1.2008
Alternative names Kuikka
Deposit summary KUIKKAPURO, in the Suomussalmi greenstone belt, has an in situ resource estimate of 800 kg gold, with an average grade of 14.6 g/t Au (unclear if the resource calculation is JORC-compliant). It is an Archaean orogenic gold deposit in tholeiitic metabasalt in a second-order, D3 to D4, NNW-trending, lithology-parallel, ductile shear zone. Alteration mineral assemblages (biotite-calcite) indicate mineralisation under amphibolite-facies conditions. Coarse, free native gold in quartz veins and their immediate, intensely biotitised host rock.
LOCATION
Geological domain Archaean Belt Suomussalmi
Site photo kuikkapuro_maintrench180803_th Regional map kareliamap1_th
Map sheet 451110
Northing (kkj) 7228710 Easting (kkj) 4455850
Latitude 65.15171N Longitude 29.05530E
Municipality Suomussalmi
Nearest town, roads 27 km N from Suomussalmi, 5 km from sealed road, a gravel road to the area.
MINING
Exploration licence no 6748/1–4, 6841/1, 6880/1–2, 6912/1 Mining concession no  
Present holder OPEN FOR ACQUISITION
Previous holders Geological Survey of Finland (GTK) (1996–2001), Outokumpu Oyj (2001–2003), Polar Mining (2003–2006)
Infra fig 1 kianta_inframap_th Infra fig 2  
Claim fig 1 kianta_claim_map_th Claim fig 2  
Mine photo 1   Mine photo 2  
Mine photo 3   Mine photo 4  
Status of development Prospect
When mined  
Resources 0.054 Mt @ 14.6 ppm Au [4,5].
Deposit size (Mt) 0.054 Reference (size) [4,5]
Total in-situ gold (kg) 800 Reference (in-situ Au) [4,5]
Total gold production (kg)   Reference (gold prod)  
Production of other metals  
Extent of mineralisation 1 km long, 15–30 m wide, dips at 60° to the ENE [4,5].
Lodes At least one lode [1].
Best sections 0.7 m @ 183 ppm, 1 m @ 115 ppm, 16 m @ 19.0 ppm, 1 m @ 54 ppm, 3 m @ 11.4 ppm, 2 m @ 26.2 ppm, 4.4 m @ 8.6 ppm, 6.8 m @ 1.8 ppm Au [4,5].
EXPLORATION
Discovery year 1997
Discovery By GTK: first indications were a regional Au anomaly in till and an auriferous sample from a glacial erratic boulder, provided by an amateur prospector; further indications were the high Au, As and Te concentrations detected by percussion drilling into till-bedrock interface; the deposit was detected by drilling by GTK: the first hole intersected ore [1,4,5].
Exploration history GTK (1994–1999) [1,4,5,7,10]: Bedrock mapping, till geochemical survey, percussion drilling into till-bedrock interface, diamond drilling, low-altitude airborne magnetic, electromagnetic and radiometric survey, and magnetic, slingram and IP ground survey, structural and ore mineralogy studies.
Outokumpu (2001–2002) [10]: palaeo-stress modelling.
Section figure 1 kuikka_section_th Plan figure 1 kuikka_plan_drilling_th
Section figure 2   Plan figure 2 kiannanniemi_geology_geophys_tillgeochem_th
Section figure 3   Plan figure 3 kuikka_trench_m1_geology_saarela2005_th
Section figure 4   Plan figure 4 kuikka_trench_m2_geology_saarela2005_th
Trench fig 1 kuikkapuro_secondtrench180803_th Trench fig 4  
Trench fig 2 kuikkapuro_view_north_2trench_280905txt_th Trench fig 5  
Trench fig 3 kuikkapuro_along_strike_mineralisation2_maintrench_160506_th Trench fig 6  
Explor site photo 1   Explor site photo 2 kianta_claim_map_th
Geophysical response IP indicated the pyrite-rich horizons and ground-magnetic survey possible shear or fault zones; no specific response by slingram [4].
Drilling GTK (1996–1999) [4,5,7]: 52 diamond-drill holes, total 4359 m.
Elements analysed All samples by ICP-AES for As, Ca, Cd, Co, Cr, Cu, Fe, K, Mg, Mn, Mo, Ni, P, Pb, S, Sb, Sr, Ti, V and Zn; in addition Ag, Co, Cr, Cu, Fe, Mn, Ni, Pb, Zn by AAS, Au and Te by GFAAS; Al, As, Ba, Bi, Ca, Ce, Cl, Cr, Cu, Fe, Ga, K, La, Mg, Mn, Mo, Na, Nb, Ni, P, Pb, Rb, S, Sb, Sc, Si, Sn, Sr, Th, Ti, U, V, Y, Zn, Zr by XRF [4,5].
Primary dispersion Au and As anomalies; however, Au and As do not show a strong positive correlation with each other [7], but in [10] it is stated that gold shows a positive correlation with As and Te.
Secondary dispersion Extensive Au-Te anomaly in till [7].
Primary anomaly fig 1 kianta_electricmap_th Secondary anomaly fig 1 kianta_as_map_th
Primary anomaly fig 2 kianta_magneticmap_th Secondary anomaly fig 2 kianta_au_map_th
Primary anomaly fig 3 sgb_aeromag_th Secondary anomaly fig 3 sgb_au_as_te_map_th
Primary anomaly fig 4 kuhmo_suomuss_modified_regional_aerogeophys_th Secondary anomaly fig 4  
Primary anomaly fig 5   Secondary anomaly fig 5  
Economic evaluations  
Exploration geologist in charge GTK: Kimmo Pietikäinen; Outokumpu: Jukka Jokela
ORE
Siting of gold Free gold in quartz veins, closely associted with arsenopyrite, grain size up to one millimetre [1,4], but on average 10-30 μm [10]. Highest Au content is in quartz veins immediately below hanging wall [7].
Fineness 84.3–89.4% Au, 10.1–14.6% Ag [4].
Major opaques Arsenopyrite, pyrite, pyrrhotite [4].
Minor opaques Ilmenite, chalcopyrite, pyrite, bravoite, pentlandite, cobaltite, sphalerite, galena, molybdenite, löllingite, covellite, talnakhite, native gold, wolframite, zincian chrome spinel, stibiopalladinite, altaite, hessite, petzite, sylvanite, tsumoite, volynskite [10].
Gangue Quartz, biotite, K feldspar, epidote, scheelite [4,10].
Ore miner. photo 1 kuikka_ore_micrograph_th Ore miner. photo 5  
Ore miner. photo 2 kuikka_siting_of_gold1_saarela2005_th Ore miner. photo 6  
Ore miner. photo 3 kuikka_siting_of_gold2_saarela2005_th Ore outcrop photo 1  
Ore miner. photo 4   Ore outcrop photo 2  
Ore composition  
Enriched elements Deduced in reference [10] from mineral assemblages (mass balance not evaluated): Ag, Al, As, Au, Ba, Co, Cr, Fe, Mn, Mg, Ni, CO2, K, P, Pb, S, Si, Sr, Te, Ti, V, W.
Ore fluid  
Stable isotopes  
Pb isotope data  
GEOLOGY
Geological setting The deposit is in the southern part of the late Archaean Suomussalmi Greenstone Belt and is in the rocks of the 2.8-2.7 Ga(?) Saarikylä Group of the greenstone belt [1,3,10]. It is in a sequence dominated by mafic and intermediate metavolcanic rocks (occasionally pillowed mafic lavas and intermediate to mafic tuffs or tuffites) with minor metakomatiitic units, in a contact zone between mafic and intermediate to felsic units, in an overturned antiform [4,8,10].
Major host rocks Tholeiitic basalt [4].
Minor host rocks  
Intrusives [1,2,3]: TTG granitoids, from 2739±8 Ma to 2697±10 Ma of age, are abundant within and near the greenstone belt. The alteration halo is cut by an unaltered dolerite dike, which resembles dykes of a Proterozoic dyke swarm cutting the greenstones of the Suomussalmi Greenstone Belt [4]. In the Kiannanniemi area, there apparently are Palaeoproterozoic dolerite dykes of three ages, all clearly postdating gold mineralisation [7].
Regional geol map 1 suomussalmi_map_thumb Outcrop photo 1  
Regional geol map 2 suomussalmi_beltmap2_th Outcrop photo 2  
Local geology map 1 kuikka_plan_drilling_th Outcrop photo 3  
Local geology map 2 kiannanniemi_regionmap_th
METAMORPHISM
Metamorphic history  
Metamorphic grade Lower-amphibolite facies [1,3] or upper-greenschist facies [8].
Metamorphic mineral assemblages Mafic volcanic rock: plagioclase-hornblende-titanite-K feldspar ± quartz, ilmenite, zircon, pyrrhotite, chalcopyrite [10].
Metamorph photo 1 kuikka_unaltered_mafic_th Metamorph photo 2  
STRUCTURE
Structural style Ductile [4], ductile-brittle [10].
Closest major shear  
Controlling structure The mineralisation is within a second-order D3 or D4 fault or shear zone [1], apparently parallel to the strike and dip of the lithological units [4,8] or cuttig them in a low angle [10].
Deformation history At least, four deformation stages during the late Archaean and two deformation stages during the Palaeoproterozoic time detected in the area [1,3]. NW- and SW-trending shear zones and joints cut the axial plane foliation and the mineralized zones - these may be associated with emplacement of Proterozoic dolerite dikes [5]. Age of D2 is probably 2820±15 Ma [7] or 2843±18 Ma [10]. Syn-D3 granodiorite suggests an age of ca. 2718 Ma for the D3 stage [7].
Ore fabric  
Veins Quartz veins 1 cm to 1 m thick [1,4,7].
Structure photo 1 kuikka_trench_m1_structure_saarela2005_th Vein photo 1  
Structure photo 2   Vein photo 2  
Structure photo 3   Vein photo3  
ALTERATION
General alteration Formation of biotite-rich and granet-biotite rich mineral assemblages [1]. The obvious alteration halo charcterised by biotite+quartz is 10–30 m wide [4]. To the west, the proximal alteration grades into granet-biotite alteration (reflecying a change in primary rock type?) [4,7].
Proximal alteration Metabasalt: quartz-biotite-calcite-ankerite-titanite [1,4,10].
Intermediate alteration  
Distal alteration Tuff or tuffite: granet-biotite-plagioclase-quartz-chlorite [1,4,8]; unclear if the garnet is at all a product of alteration [8].
Mafic volcanic rock: quartz-biotite-chlorite-epidote partially replace the primary assemblage [10].
Zonation figure   Prox alteration photo 1  
Alteration photo 1 kuikka_unaltered_mafic_th Prox alteration photo 2  
Alteration photo 2 kuikka_biot_zone_th Intermed alteration photo  
Alteration photo 3 kuikka_gar_biot_zone_th Distal alteration photo1  
Post-mineralisation modifications Possibly, a retrograde overprint at greenschist-facies PT conditions [3], also suggested by the late formation of chlorite and epidote [4]. In addition, formation of NW- and SW-trending shear zones, possibly during the Proterozoic [4]. Weak retrograde overprint, D5 deformation with barren quartz-epidote veins
TIMING Syn- or slightly post-peak metamorphic [1], syn-D3 to D4 [10].
GENETIC MODEL Formed soon(?) after the peak metamorphic event under slightly retrograde conditions near the ductile-brittle transition. An orogenic "mesothermal" deposit with a distinct structural control and having formed under amphibolite-facies conditions [4,10], formed during late-Archaean cratonisation [6].
GENETIC TYPE Orogenic References [1,4,6,10]
Alternative genetic type 1   References  
Alternative genetic type 2   References  

References

1. Halkoaho, T. & Pietikäinen, K. 1999. Ni and Au prospects of the Kuhmo and Suomussalmi greenstone belts. In: H. Papunen & P. Eilu (eds.) Geodynamic Evolution and Metallogeny of the Central Lapland, Kuhmo and Suomussalmi Greenstone Belts, Finland. University of Turku, Inst. Geol. Mineral. Publ. 42, 60–63.
2. Poutiainen, M. & Luukkonen, E. 1994. The geology and fluid inclusion studies of some epigenetic gold deposits in the Archean Kuhmo and Suomussalmi greenstone belts, eastern Finland. In: M. G. Izquierdo, A. M. C. Suarez, G. M. Guevara, D. Vanko & G. J. C. Viaggio (eds) Fifth Biennial Pan-American Conference on Research on Fluid Inclusions, Cuernavaca, Morelos, Mexico, May 19–21, 1994. Abstracts, 77–78.
3. Luukkonen, E. 1992. Late Archaean and Early Proterozoic structural evolution in the Kuhmo-Suomussalmi Terrain, eastern Finland. Annales universitatis Turkuensis. Ser. A. II 78, 1–37.
4. Pietikäinen, K., Hartikainen, A., Niskanen, M. & Tenhola, M. 2001. The gold prospects; Kuikka, Syrjälä N, Syrjälä S and Tupakkiloma in Kiannanniemi, Suomussalmi, Eastern Finland. www.gtk.fi/explor/tender/Kuikka/kuikka.htm
5. Heino, T. 2000. Mineral Resource Assessment of the Kuikkapuro 1 (mine reg. no. 6748/1), Kuikkapuro 2 (no. 6841/1), Kuikkapuro 3 (no. 6880/1), Kuikkapuro 4 (no. 6880/2) and Kuikkapuro 5 (no. 6912/1) gold mineralizations. Associated with the Geol. Surv. Finland, Report CM06/4511/2000/1.
6. Papunen, H., Halkoaho, T., Liimatainen, J. & Luukkonen, E. 2001. Metallogeny of the Archaean Tipasjärvi-Kuhmo-Suomussalmi greenstone belt, Finland. AGSO – Geoscience Australia, Record 2001/37, 456–458.
7. Luukkonen, E., Halkoaho, T., Hartikainen, A., Heino, T., Niskanen, M., Pietikäinen, K. & Tenhola, M. 2002. Itä-Suomen arkeeiset alueet -hankkeen (12201 ja 210 5000) toiminta vuosina 1992–2001 Suomussalmen, Hyrynsalmen, Kuhmon, Nurmeksen, Rautavaaran, Valtimon, Lieksan, Ilomantsin, Kiihtelysvaaran, Enon, Kontiolahden, Tohmajärven ja Tuupovaaran alueella. Geol. Surv. Finland, Report M19/4513/2002/1. 265 p. (in Finnish, 130 MB)
8. Ojala, J. 2006. Personal communication 16 May 2006.
9. Goode, K. 2004. Dragon Mining NL (DRA) – Bringing Scandinavian Gold Mines into Production. 12 p. (938 KB)
10. Sorjonen-Ward, P. & Luukkonen, E.J. 2005. Archean rocks. In: Precambrian Geology of Finland – Key to the Evolution of The Fennoscandian Shield. Elsevier Science B.V., Amsterdam, 19–9 9.
11. Saarela, P. 2005. Kullan esiintymistä kontrolloivat rakennegeologiset tekijät Suomussalmen Kuikkapurolla. MSc thesis. Dept of Geosciences, Univ. of Oulu. 53 p. (in Finnish)
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