The Vaara region is located within the northern portion of the Suomussalmi Greenstone Belt and consists of a north to north-northeast striking sequence of mafic, ultramafic and felsic rocks. It contains five large (up to 3 kilometres x 0.5 kilometres) serpentinite (ex-olivine cumulate) lenses. The lenses are developed within a complex and poorly known sequence of komatiite flow units, mafic rocks and discontinuous meta-sedimentary units over approximately 15 kilometres of strike dipping steeply to the east. From north to south, the cumulate lenses are known as the Kauniinlampi, Hoikkalampi, Rytys, Vaara and Portti lenses. Nickel mineralisation within these lenses has been discovered in drill holes or in outcrop at Vaara, Kauniinlampi (north, central and south) and Hoikkalampi. In addition, nickel sulphide mineralisation has been discovered in footwall komatiite units west of the Vaara lens.
At Vaara, disseminated nickel sulphide mineralisation is developed within a serpentinised olivine ortho-mesocumulate with MgO content varying between 40-42.5%. Several southwest-northeast trending serpentinite and associated chlorite-amphibole rock units can be identified within the Vaara komatiitic complex. These ultramafic rocks are enveloped by felsic and mafic volcanic rocks and related metasedimentary rocks.
The deposit occurs within the western-most of the thick cumulate bodies interpreted to be east facing. A north-south trending zone of mineralisation has been traced for approximately 450 metres along strike. The thickness of the deposit varies between two to three metres at its northern part and up to 60 metres thick at the south. The vertical depth of the known deposit is limited by drilling from 50 metres in the north to 170 metres in the south. In general, the deposit remains open at depth and the average nickel grade is between 0.3% and 0.6% nickel, with a highest value of 1.99% nickel. The nickel tenor is high being 20-50%.
The best intercept in GTK’s drilling programme was in hole R656, returning 10 metres at 1.15 % nickel, 0.15 % copper, 0.023 % cobalt, 1.63 % sulphur and 0.69ppm palladium. Platinum has not been assayed.
Universal has completed three infill and exploration drilling programmes at Vaara. Majority of the drilling was planned to infill GTK`s drilling at the mineralised parts of the cumulate body. In addition to in-fill drilling Kuhmo also drilled several exploration holes mainly at the western and south western sides of the mineralised cumulate. Holes were targeting multiple geophysical and geochemical (MMI) targets at the interpreted footwall zone. A total of 43 holes and 4,608m were drilled during 2005 – 2008 programmes.
Significant results from recent Universal drilling programmes
| Hole | From (m) |
Interval (m) |
Ni (%) |
Cu (%) |
Co (%) |
Pd (ppm) |
Pt (ppmt) |
2PGE (ppm) |
| SMS/SK-50 | 22.30 | 6.40 | 0.59 | 0.05 | 0.01 | 0.27 | 0.11 | 0.38 |
| SMS/SK-53 | 74.00 | 15.00 | 0.42 | 0.03 | 0.01 | 0.17 | 0.07 | 0.24 |
| SMS/SK-54 | 26.00 | 25.00 | 0.69 | 0.06 | 0.02 | 0.37 | 0.16 | 0.53 |
| SMS/SK-56 | 30.00 | 43.00 | 0.43 | 0.03 | 0.01 | 0.21 | 0.10 | 0.31 |
| SMS/SK-57 | 9.00 | 8.80 | 0.70 | 0.04 | 0.02 | 0.43 | 0.18 | 0.61 |
| SMS/SK-60 | 9.00 | 10.00 | 0.66 | 0.07 | 0.02 | 0.36 | 0.16 | 0.52 |
The Kauniinlampi ultramafic lens is between 200 and 500 metres wide, 2,300 to 3,400 metres long and hosts three nickel occurrences.
The main prospect is Kauniinlampi North where nickel is interpreted to be associated with a north-west trending, north-east dipping fault. This nickel occurrence occurs as fine grained sulphide dissemination in a sheared serpentinised olivine ad-mesocumulate unit. The occurrence is up to 20 metres thick and 100 metres long and nickel content varies between 0.2%-1.0%. The principal nickel mineral is pentlandite with lesser heazlewoodite.
The GTK intersected the Kauniinlampi North occurrence with 11 holes at shallow depths, 40 – 120 metres vertical depth and remains open north, south and downwards.
The Kauniinlampi Central occurrence is as undeformed and in-situ and comprises disseminated pyrrhotite and pentlandite hosted by olivine cumulate with nickel values typically less than 0.5%. This nickel occurrence has been intersected by 9 holes drilled by the GTK. One to three zones less than 5 metres thick of disseminated nickel bearing sulphides have been reported within serpentinised olivine cumulate. The occurrence has been drilled mainly at shallow levels and up to 200 metres vertical depth. As with the Kauniinlampi North, the drill density is sparse and the occurrence remains open north, south and at depth.
Drilling at Kauniinlampi South is very sparse with the closest drilling profiles 150 metres north and 400 metres south of the occurrence intersected to date. Mineralisation has been intersected in only two drill holes and the nature of the occurrence is not well established. The highest nickel value is 0.65%, returned from serpentinite hosted disseminated sulphides. Generally the occurrence is a few metres thick with nickel grades less than 0.4%.
Between 1994-2001, GTK and Outokumpu drilled 39 drill holes into the Hoikkalampi komatiitic cumulate lens. Disseminated sulphides were intersected within serpentinitised olivine cumulates at two locations in the southern and eastern part of the cumulate lens. The highest nickel value is 0.38% over a metre. Drill density is sparse and the continuity of this weak mineralisation is still unknown. One nickel bearing serpentinite boulder was found east of Hoikkalampi grading 0.97% nickel, 0.15% copper and 4.4% sulphur.
Two nickel bearing serpentinite boulders have been found at the southern tip of the Rytys cumulate lens grading 0.38% and 0.44% nickel. These boulders are the only showings of nickel mineralisation in Rytys cumulate lens. The GTK completed 1,656 metres of diamond drilling in 16 holes during drilling programmes in 1990’s. No mineralisation was intersected.