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The Råna Intrusion is located approximately 20 km southwest of Narvik, in the municipality of Narvik, northern Norway.
Råna ApS, a fully owned subsidiary of Scandinavian Highlands Holding A/S, holds 15.5 km2 exploration licences covering the majority of the ultramafic rocks exposed along the northern intrusion boundary. The now closed Bruvann mine is located within the licence area. The Norwegian State holds the mining claims and Bruvann ApS (also a fully owned subsidiary of Scandinavian Highlands Holding A/S) has subsequently rented them.
Existing infrastructure is in place in and partly around the intrusion. The project has good access routes; having the main trans-Norwegian road (E6) crossing the northern part of the intrusion, along the shore of the Ofotfjord. Quay and loading facilities are also in immediate vicinity of the intrusion.
The license area is an Early Silurian (ca 437 Ma) synorogenic mafic-ultramafic intrusion. The intrusion was emplaced during the Caledonian orogeny and is situated in the Upper Allochton, of the Narvik Nappe Complex (NNC), Caledonides of Norway. The intrusion covers an area of approximately 70 km2. Caledonian sulphidic metasedimentary rocks are well known in the NNC. The Råna Intrusion is located in proximity of several old past producing sulphide mines. The presence of sulphidic country rock is highly important and of ore genetic importance for the Råna Intrusion.
The Råna intrusion has the shape of an inverted cone with its axis plunging to the north-northwest. The exposed part of the intrusion forms a nearly concentric shape with a peripheral zone of gabbro-norite containing bands and lenses of ultramafics i.e. peridotite and pyroxenite. The central part of the intrusion is dominated by quartz-norite. The lithostratigraphy thus resembles many layered intrusions, but lack primary structures due to later obliterating orogenic deformation phases. The intrusion bears witness to several deformational events, of which at least one was an isoclinal folding phase and local thrusting, shearing and minor folding is evident in many localities in the intrusion. Compared to other gabbroic intrusions, the Råna Intrusion is on a gross scale fairly homogenous, and only on the large scale is magmatic differentiation obvious.
The exploration activities carried out between 2004−2008 have followed two parallel lines. Firstly a re-evaluation of the remaining ore body in the Bruvann mine and secondly, a renewed exploration activity level focused on the fertile mafic-ultramafic cumulate rocks in the northern part of the Råna Intrusion.
The majority of the exposed ultramafics in the northern part of the intrusion are mineralised to a variable extent. Disseminated sulphides, occurring interstitial to the mafic silicate matrix by far dominate the mineralisation scheme. More erratic mineralised zones with accumulation of semi-massive sulphides are often found in relationship with assimilated country rock.
The comprehensive field work done in the Råna Intrusion area comprises different geophysical survey techniques, including helicopter born time domain electromagnetic surveys (TEM) , conducted by SkyTEM ApS, Denmark, ground based magnetometer (MAG) and frequency domain electromagnetic (FDEM) surveys, as well as ground based Beep-Mat surveys. Geochemical data has likewise been collected to a great extent. In addition to hundreds of surface rock grab samples and stream sediment samples, more than 4000 soil samples have been collected within the license area.
Combining the extensive data-sets formed the basis for two diamond drill campaigns, undertaken in autumn 2006 and 2007, totaling 3982 m. New mineralisations were intersected during both drill campaigns. The intersections include minor massive sulphide veins, massive to semi-massive sulphide breccias and basal disseminated sulphide mineralisations in ultramafic cumulate rocks. Sulphide mineralisation consists predominantly of pyrrhotite, pentlandite, chalcopyrite and lesser amounts of pyrite. The geological environment and the encountered mineralisations are regarded as good indicators for larger ore-potential.
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