Active and ongoing gold exploration and mining in ... - IAGS 2011

was discovered in 1986 during diamond drilling by
GTK. A total of 77 diamond drill holes (9,320 metres)
were completed by GTK, outlining a resource
of 1.5 Mt with an average grade of 5.9 g/t (285,000
ounces of gold) by 1997 (Parkkinen 1997). In April
1998, the deposit was acquired by Riddarhyttan
Resources AB and the company’s exploration activities
increased the resource size to over 2 million
ounces of gold (Bartlett 2002). Ore-grade mineralisation
was found over a five-kilometre strike length
of the KiSZ in similar structural and stratigraphic
positions. Mine feasibility studies on Suurikuusikko
began in winter 2000. In 2004, Agnico-Eagle
Mines Limited acquired a 14 % ownership interest
in Riddarhyttan, and in 2005 acquired the remaining
Riddarhyttan shares. In June 2006, a decision
was made to begin mine development. The Kittilä
Mine achieved commercial production in May 2009.
Geology
Fig. 8. Geology in the vicinity of the Kittilä Mine and KiSZ.
Geological map is derived on the current GTK digital bedrock map database.
Suurikuusikko occurs within greenschist-facies
metavolcanic rocks of the ca. 2.0 Ga Kittilä Group
(Fig. 8; Lehtonen et al. 1998). Geochemical heterogeneity
among the Kittilä Group rocks has been
interpreted to indicate that the Group is a composite
of arc terranes and oceanic plateaux amalgamated
during oceanic convergence (Hanski & Huhma
2005). Significant variations in metamorphic
grade within the Group also suggest that a number
of distinct lithological elements could be present
within the area currently mapped as Kittilä Group,
and seismic surveys across central Lapland indicate
a number of distinct crustal blocks (Patison et
al. 2006b). The maximum current thickness of the
Kittilä Group is between six and seven kilometres
(Luosto et al. 1989) in the Kittilä Mine area.
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