Timanttimaa - Gold Database

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Name	Timanttimaa	DATA UPDATED	12.1.2007
Alternative names
Deposit summary	TIMANTTIMAA, in Southern Ostrobothnia, has an in situ resource estimate of 500 kg gold (no JORC-compliant resource calculation is available). It is a Palaeoproterozoic orogenic gold deposit comprising an auriferous quartz vein network in felsic plagioclase porphyry and tonalite. The deposit is close to a NE-trending shear zone. Chiefly free gold in quartz veins.
LOCATION
Geological domain	Svecofennian	Belt	Southern Ostrobothnia
Site photo		Regional map
Map sheet	222203
Northing (kkj)	6940000	Easting (kkj)	2463000
Latitude	62.56276N	Longitude	23.27706E
Municipality	Alavus, Peräseinäjoki
Nearest town, roads	10 km E from Peräseinäjoki, about 30 km SSE from Seinäjoki. A sealed road 1 km from the area, a minor gravel road to the area.
MINING
Exploration licence no	4186/1	Mining concession no
Present holder	OPEN FOR ACQUISITION
Previous holders	Geological Survey of Finland (GTK)
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)	500	Reference (in-situ Au)	[2]
Total gold production (kg)		Reference (gold prod)
Production of other metals
Extent of mineralisation	Total thickness about 20 m [1].
Lodes
Best sections	1.5 m @ 15.5 ppm Au; 3 m and 1.4 m @ 1.8 ppm Au [1,2].
EXPLORATION
Discovery year	1986
Discovery	First indications were outcrop samples provided by amateur prospectors in 1986; this was followed, by GTK, by the discovery of a till geochemical anomaly and then bedrock mapping and sampling led to the actual discovery [1,2].
Exploration history	GTK (1987–1991) [1,2]: till geochemical survey, bedrock mapping, trenching, electric and magnetic ground survey, 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	Three of the five IP anomalies in the area indicate the locations of the weakly sulphidised, auriferous shear zones [2].
Drilling	GTK (1987–1991 [1,2]: 9 diamond-drill holes, total 910 m, with 20–70 m distances between the holes.
Elements analysed	As, Au, Cu [1].
Primary dispersion
Secondary dispersion	A combined Au-As-Cu anomaly in till extends, apparently, hundreds of metres from the mineralisation along the trend of glacial transport [2].
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: Niilo Kärkkäinen.
ORE
Siting of gold	Chiefly free gold in quartz veins [2].
Fineness
Major opaques	Pyrrhotite, arsenopyrite [2].
Minor opaques	Chalcopyrite, gold [2].
Gangue	Quartz, carbonate, chlorite, scheelite [2].
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
Enriched elements
Ore fluid
Stable isotopes
Pb isotope data
GEOLOGY
Geological setting	The mineralisation is in the contact zone between the synorogenic Haapaluoma tonalite and the intermediate metavolcanic rock [2]. This "metavolcanic rock" (i.e. the major host rock) may, actually, be a volcanogenic metasedimentary rock.
Major host rocks	Dacitic plagioclase porphyry [1,2].
Minor host rocks	Tonalite [2].
Intrusives	Synorogenic Haapaluoma tonalite which predates gold mineralisation [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	Brittle-ductile [1,2].
Closest major shear	A NE-trending Shear zone adjacent to the area [1].
Controlling structure	A set of silicified, 1–10 m wide shear zones in the host rock [1,2].
Deformation history
Ore fabric
Veins	An auriferous quartz vein network [1].
Structure photo 1		Vein photo 1
Structure photo 2		Vein photo 2
Structure photo 3		Vein photo 3
ALTERATION
General alteration	Formation of biotite, carbonate and chlorite? [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	Orogenic "mesothermal" deposit.
GENETIC TYPE	Orogenic	References
Alternative genetic type 1		References
Alternative genetic type 2		References
References 1. Kärkkäinen, N. 1993. Kultamalminetsintää Peräseinäjoen ja Alavuden Timanttimaalla vuosina 1987–1991. Geol. Surv. Finland, Report M19/2223/-92/1/10. 25 p. (in Finnish, 5.8 MB) 2. Kärkkäinen, N. 1993. Tutkimustyöselostus Alavuden kunnassa (Timanttimaalla) valtausalueella Koukkuluomanmaa 1, kaiv.rek.nro 4186/1 suoritetuista malmitutkimuksista. Geol. Surv. Finland, Report. M06/2223/-93/1/10. 5 p. (in Finnish, 3 MB)
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