Sudenkylä - Gold Database

Back to Gold map			Alphabetical list
Name	Sudenkylä	DATA UPDATED	12.1.2007
Alternative names	Haudankylä
Deposit summary	SUDENKYLÄ (HAUDANKYLÄ), in Southern Ostrobothnia, is a Palaeoproterozoic orogenic gold occurrence with no resource estimate available. It is hosted by mica gneiss, and located between two major NW-trending shear zones.
LOCATION
Geological domain	Svecofennian	Belt	Southern Ostrobothnia
Site photo		Regional map
Map sheet	222204
Northing (kkj)	6950500	Easting (kkj)	2437100
Latitude	62.65344N	Longitude	22.76967E
Municipality	Ilmajoki
Nearest town, roads	15 km SW from Seinäjoki. A sealed road 7 km from the mineralisation, a gravel road adjacent to the area.
MINING
Exploration licence no	6136/1	Mining concession no
Present holder	OPEN FOR ACQUISITION
Previous holders	Geological Survey of Finland (GTK) (1981–86), Malmikaivos Oy (1986–), Outokumpu Oyj
Mine photo 1		Mine photo 2
Mine photo 3		Mine photo 4
Status of development	Prospect
When mined
Resources
Deposit size (Mt)		Reference (size)
Total in-situ gold (kg)		Reference (in-situ Au)
Total gold production (kg)		Reference (gold prod)
Production of other metals
Extent of mineralisation
Lodes
Best sections	1 m @ 3.5 ppm Au [3].
EXPLORATION
Discovery year	1986
Discovery	By Malmikaivos Oy; the first indication was an aurideforus glacial erratic found by an amateur prospector; the occurrence was found by a follow-up exploration on an Au anomaly in till detected during regional till geochemical survey [3].
Exploration history	GTK (1981–86) [2,3]: Regional and localised till geochemical survey, till stratigraphy and bedrock mapping. Malmikaivos (1986–) [4]: Bedrock mapping, diamond drilling?.
Section figure 1		Plan figure 1
Section figure 2		Plan figure 2
Section figure 3		Plan figure 3
Trench fig 1		Trench fig 4
Trench fig 2		Trench fig 5
Trench fig 3		Trench fig 6
Explor site photo 1		Explor site photo 2
Geophysical response
Drilling
Elements analysed
Primary dispersion
Secondary dispersion	An Au anomaly 600x600 m in size in till; the regional Sb and As anomalies in till are, apparently, unrelated to gold mineralisation [2,3].
Primary anomaly fig 1		Secondary anomaly fig 1
Primary anomaly fig 2		Secondary anomaly fig 2
Primary anomaly fig 3		Secondary anomaly fig 3
Primary anomaly fig 4		Secondary anomaly fig 4
Primary anomaly fig 5		Secondary anomaly fig 5
Economic evaluations
Exploration geologist in charge	GTK: Pekka Lestinen; Malmikaivos: Pertti Huopaniemi.
ORE
Siting of gold
Fineness
Major opaques	Arsenopyrite, pyrrhotite, pyrite(?) [3].
Minor opaques
Gangue
Ore miner. photo 1		Ore miner. photo 5
Ore miner. photo 2		Ore miner. photo 6
Ore miner. photo 3		Ore outcrop photo 1
Ore miner. photo 4		Ore outcrop photo 2
Ore composition	Diamond-drill core [1]: 10.80 ppm Au, 0.70 ppm Ag, 30000 ppm As, 3.0 ppm B, 475 ppm Ba, 19.2 ppm Bi, 999 ppm Co, 632 ppm Cu, 210 ppb Hg, <1 ppm Mo, 775 ppm Ni, 5 ppm Pb, 91 ppm Rb, 104000 ppm S, 2.3 ppm Sb, 7.9 ppm Se, 82 ppm Sr, 5.600 ppm Te, 1.8 ppm Th, 1.6 ppm U, 120 ppm V, <0.5 ppm W, 70 ppm Zn; 46.2% SiO2, 0.49% TiO2, 5.56% Al2O3, 31.5% Fe2O3, 2.66% MgO, 2.28% CaO, 1.60% Na2O, 2.76% K2O, 0.039% P2O5, 9.00% LOI.
Enriched elements	Au, Ag, As, Bi, Co, Cu, Hg, K, Rb, S, Sb, Se, Te [1].
Ore fluid
Stable isotopes
Pb isotope data
GEOLOGY
Geological setting	A sequence of palaeoproterozoic metapelites and metagreywackes intruded by the intermediate plagioclase and plagioclase-uralite porphyry sills(?) [2,3,5].
Major host rocks	Mafic metavolcanic rock [1]; mica gneiss [3].
Minor host rocks
Intrusives
Regional geol map 1		Outcrop photo 1
Regional geol map 2		Outcrop photo 2
Local geology map 1		Outcrop photo 3
Local geology map 2
METAMORPHISM
Metamorphic history
Metamorphic grade
Metamorphic mineral assemblage
Metamorph photo 1		Metamorph photo 2
STRUCTURE
Structural style
Closest major shear	The mineralisation is between two NW-NNW trending, major shear zones [2,3,5].
Controlling structure
Deformation history
Ore fabric
Veins
Structure photo 1		Vein photo 1
Structure photo 2		Vein photo 2
Structure photo 3		Vein photo 3
ALTERATION
General alteration
Proximal alteration
Intermediate alteration
Distal alteration
Zonation figure		Prox alteration photo 1
Alteration photo 1		Prox alteration photo 2
Alteration photo 2		Intermed alteration photo
Alteration photo 3		Distal alteration photo 1
Post-mineralisation modifications
TIMING
GENETIC MODEL	Orogenic "mesothermal" deposit.
GENETIC TYPE	Orogenic, Au-Sb subtype	References
Alternative genetic type 1		References
Alternative genetic type 2		References
References 1. Nurmi, P. A., Lestinen, P. & Niskavaara, H. 1991. Geochemical characteristics of mesothermal gold deposits in the Fennoscandian Shield, and a comparison with selected Canadian and Australian deposits. Geol. Surv. Finland, Bull. 351. 101 p. 2. Lestinen, P. 1988. Seinäjoen alueen geokemialliset tutkimukset vuosina 1983–1986. Geol. Surv. Finland, Report S/41/2222/1/1988. 40 p. (in Finnish, 1.4 MB) 3. Lestinen, P., Kontas, E., Niskavaara, H. & Virtasalo, J. 1991. Till geochemistry of gold, arsenic and antimony in the Seinäjoki district, western Finland. Journal of Geochemical Exploration 39, 343–361. 4. Tyni, M. 1983. Lausunto Kalliosalon antimoniesiintymän hyväksikäyttömahdollisuuksista. A letter by Malmikaivos Oy to the Ministry of Trade and Industry. 3 p. (in Finnish) 5. Korsman, K., Koistinen, T., Kohonen, J., Wennerström, M., Ekdahl, E., Honkamo, M., Idman, H. & Pekkala, Y. (eds.) 1997. Suomen Kallioperäkartta = Berggrundskarta över Finland = Bedrock map of Finland 1:1 000 000. Geol. Surv. Finland.
Back to Gold map			Alphabetical list