Mäntysaari - ZINC Database

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Name	Mäntysaari	DATA UPDATED	15.10.2001
Secondary names
Site photo 1		Site photo 2
LOCATION
Geological domain	Svecofennian	Province	Salo-Issakka
Regional map 1		Regional map 2
Map sheet	313411
Northing	6783650	Easting	3572150
Latitude	61.15516N	Longitude	28.33691E
Municipality	Taipalsaari
Nearest town, access	12 km NE from Lappeenranta, on a small island which is 250 m from the shore. Eight km to a sealed road, 500 m to a gravel road. Along the roads, about 20 km to railway.
MINING
Mine photo 1		Mine photo 2
Mine photo 3		Mine photo 4
Exploration licence no		Mining concession no
Present holder	OPEN FOR ACQUISITION
Previous holders	Outokumpu Oyj
Status of development	Drilled prospect
When mined
Resources and grades
Total production
Total in-situ content
Size of the deposit (Mt)		Size reference
Best sections	2.2 m @ 2.1% Zn, 0.76% Cu,13 ppm Ag; 2.35 m @ 1.0% Zn, 0.38% Cu [1].
Extent of the deposit	600 x 130 x 10 m [1].
Ore bodies	Two NW-trending, steeply SW-dipping, lodes in the same 'horizon' [1,3].
Plan figure 1		Plan figure 2
Plan figure 3		Plan figure 4
Section figure 1		Section figure 2
Section figure 3		Section figure 4
EXPLORATION
Explor. site photo 1		Explor. site photo 2
Discovery year	1979
Discovery	By Outokumpu; first indications were mineralised glacial erratics found in 1973–1975 by amateur prospectors; the deposit was detected by diamond drilling into an electric anomaly within an extensive magnetic anomaly in an area where a Zn-Cu mineralised outcrop was detected in 1978 by Outokumpu [1].
Exploration history	Outokumpu (1973–79) [1]: Bedrock mapping, glacial erratic survey, trenching, ground magnetic, charged potential and slingram survey, diamond drilling.
Drilling	Outokumpu: six diamond-drill holes, total 1119 m [1].
Trench figure 1		Trench figure 2
Elements analysed	Ag, As, Co, Cu, Fe, Ni, S, Zn by AAS+Leco [1].
Economic evaluations
Geophysical response	Magnetic and, especially, a distinct electric response: the deposit is a small electric anomaly within a larger magnetic anomaly [1].
Geophys. anomaly fig. 1		Geophys. anomaly fig. 2
Petrophysics
Primary geochemical dispersion
Secondary geochemical 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
Exploration geologist(s) in charge	Outokumpu: Tapio Koistinen
ORE
Ore outcrop photo 1		Ore outcrop photo 2
Major ore minerals	Pyrrhotite, sphalerite, chalcopyrite [1].
Minor ore minerals	Pyrite, arsenopyrite, loellingite [1].
Ore mineral photo 1		Ore mineral photo 2
Ore mineral photo 3		Ore mineral photo 4
Gangue
Zoning
Ore composition	Click here	Ore mineral compositions
Primary structures
Ore fabric	Sulphides are as dissemination, vein network and massive patches in the host rocks [1].
Enriched components
Geothermo- and barometry
Ore fluid
Stable isotope data
Pb isotope data
GEOLOGY
Regional geology map 1		Regional geology map 2
Local geology map 1		Local geology map 2
Geological setting	Located in a block boundary; the deposit is discordant relative to the bedding of the host rocks which form a sequence dominated by migmatitised mica gneisses (metapelites) and minor amphibolites [1].
Major host rocks	Mica gneiss [1,3,4].
Minor host rocks	Amphibolite [1].
Intrusives	The host rocks are intruded by large, 1.89–1.88 Ga, synorogenic granitoids and small synorogenic gabbros in the region; in addition, the northern exposed margin of the Mesoproterozoic Viborg rapakivi massive is 9 km to the south of the deposit [1,2,3,4].
Outcrop photo 1		Outcrop photo 2
Outcrop photo 3		Outcrop photo 4
METAMORPHISM AND DEFORMATION
Metamorphic history	Peak metamorphism is related to 1.84–1.80 microcline granites [2].
Metamorphic grade	Uppermost-amphibolite facies with a retrograde overprint [1]. Upper-amphibolite facies (Garnet-cordierite-K feldspar-biotite grade) [2].
Metamorphic mineral assemblages	Mica gneiss: biotite-quartz-plagioclase-K feldspar-cordierite-sillimanite-garnet + retrograde muscovite [1,4]. Amphibolite: cummingtonite-plagioclase-hornblende-garnet ± quartz [1].
Metamorph photo 1		Metamorph photo 2
Deformation history
Structure photo 1		Structure photo 2
ALTERATION
Regional alteration
Local alteration
Alteration figure 1		Alteration figure 2
Alteration figure 3		Alteration figure 4
Post-mineralisation modifications	Localised pyritisation of pyrrhotite during post-mineralisation stages of deformation [1].
TIMING	1.90–1.88 Ga [1,2].
SUPERGENE ALTERATION
GENETIC MODEL	The deposit was, obviously, formed during a retrogressive stage of the evolution of the area, during dominantly brittle deformation characterised by the movements of rigid blocks, at lower-amphibolite or greenschist-facies conditions [1].
GENETIC TYPE	Syngenetic remobilised	References	[1]
Alternative genetic type 1	Epigenetic shear zone-related	References	[1]
Alternative genetic type 2		References
Schematic model 1		Schematic model 2
References 1. Koistinen, T. & Ahokas, T. 1979. Tutkimusraportti. Taipalsaari, Mäntysaari. Outokumpu Oy Exploration, Report 001/3134 11A/TJK/TA/79. 14 p. (in Finnish) 2. Korsman, K. (ed.) & Glebovitsky, V. (ed.) 1999. Raahe–Ladoga Zone structure-lithology, metamorphism and metallogeny: a Finnish–Russian cooperation project 1996–1999. Map 2: Metamorphism of the Raahe–Ladoga Zone 1:1000000. Geol. Surv. Finland. 3. Vorma, A. 1964. Lappeenranta. Geological Map of Finland 1:100000: Pre-Quaternary Rocks, Sheet 3134. Geol. Surv. Finland. 4. Vorma, A. 1965. Pre-Quaternary Rocks of the Lappeenranta Map-Sheet area. Geological Map of Finland 1:100000: Explanation to the Maps of Pre-Quaternary Rocks, Sheet 3134. Geol. Surv. Finland. 72 p.
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