Putaala - Gold Database

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Name	Putaala	DATA UPDATED	24.5.2007
Alternative names	Hietaperä
Deposit summary	PUTAALA, in the southern part of the Kuhmo greenstone belt, is an Archaean orogenic gold occurrence with no resource estimate available. It is characterised by auriferous quartz veins in chlorite schist (mafic or ultramafic volcanic rock). The controlling structure is the main shear zone of the greenstone belt or a NW-trending branch of the main shear.
LOCATION
Geological domain	Archaean	Belt	Kuhmo
Site photo		Regional map
Map sheet	441303
Northing (kkj)	7121400	Easting (kkj)	4460200
Latitude	64.18984N	Longitude	29.17771E
Municipality	Kuhmo
Nearest town, roads	16 km WNW from Kuhmo. Gravel road to the area, 0.5 km to a sealed road.
MINING
Exploration licence no	7582/1–4	Mining concession no
Present holder	Geological Survey of Finland (GTK) (2003–)
Previous holders
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 @ 11.8 ppm, 1 m @ 0.6 ppm Au [1].
EXPLORATION
Discovery year	2003
Discovery	By GTK [1]: first indication was the discovery of several auriferous quartz vein glacial erratics near the Putaala farm house; this led to local bedrock mapping, ground geopysical surveys, and the occurrence wa hit by diamond drilling into positive gound magnetic anomalies and supposed fault zones in the till-covered bedrock.
Exploration history	Malmikaivos Oy (1960's) [1]: glacial erratic boulder survey, bedrock mapping, diamond drilling GTK (2002–) [1]: glacial erratic boulder survey, bedrock mapping, low-altitude airborne magnetic, electric and radiometric survey, regional and local till geochemical survey, ground magnetic, electromagnetic and IP survey, diamond drilling, relogging and reanalysis of holes drilled by Malmikaivos.
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	Malmikaivos (1960's): several diamond-drill holes [1]. GTK (2003–2004): 12 diamond-drill holes, total 1234 m [1].
Elements analysed
Primary dispersion
Secondary dispersion
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: Kimmo Pietikäinen
ORE
Siting of gold
Fineness
Major opaques	Pyrrhotite, pyrite [1].
Minor opaques	Chalcopyrite [1].
Gangue	Quartz [1].
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
Ore composition table 1		Ore composition table 2
Enriched elements	As, Au, Cu, S, Sb, Te [1].
Ore fluid
Stable isotopes
Pb isotope data
GEOLOGY
Geological setting	Mafic metavolcanic rock-dominated sequence of the southern part Late-Archaean Kuhmo greenstone belt [1].
Major host rocks	Chlorite schist [1].
Minor host rocks	Dolerite [1].
Intrusives	Archaean(?) and Palaeoproterozoic dolerites in the Archaean sequence which is bounded in the east and west by l2739–2697 Ga TTG granitoids and gneisses [1,2].
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
Controlling structure
Deformation history	At least, six deformation stages during the late Archaean and two deformation stages during the Palaeoproterozoic detected in the area; gold mineralisation is related to the Archaean late D3 and/or D4 stages; D2: 2850–2837 Ma, D3: 2701–2697 Ma, D4: peaked at 2657±32 Ma; age of D2 is probably 2820±15 Ma [2] or 2843±18 Ma [3].The latest deformation is manifested by NW-trending mylonitisation in Palaeoproterozoic dolerites [1].
Ore fabric
Veins	Auriferous and barren quartz veins [1].
Structure photo 1		Vein photo 1
Structure photo 2		Vein photo 3
ALTERATION
General alteration	Chloritisation, biotitisation, epidotisation in mafic rocks, sericitisation in mica schists [1].
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
GENETIC TYPE	Orogenic	References	[1]
Alternative genetic type 1		References
Alternative genetic type 2		References
References 1. Pietikäinen, K., Halkoaho, T., Hartikainen, A., Niskanen, M. & Tenhola, M. 2005. Itä-Suomen arkeeiset alueet II-hankkeen (2105000) toiminta vuosina 2001–2004 Kuhmon, Nurmeksen, Lieksan ja Hyrynsalmen alueilla. Geol. Surv. Finland, Report M19/4411/2005/1. 84 p. (in Finnish, 24 MB) 2. 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) 3. 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.
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