The North Fork (Krof) occurrence is located west of a south flowing tributary of Cogburn Creek, approximately 5.5 kilometres east of the mouth of Big Silver Creek on Harrison Lake.

The Cogburn Creek area is underlain by metasedimentary and metavolcanic members of the Cogburn Schist which is possibly correlative with the Permian to Jurassic Hozameen/Bridge River complexes. Granitic, gabbroic and ultramafic masses of Cretaceous to Tertiary age intrude these rocks.

In the area of the occurrence, a northwest striking, steeply east dipping sequence of medium to dark coloured, fine to medium-grained amphibole-plagioclase-quartz schist, grey to light brown, thinly-bedded to massive biotite-quartz schist, phyllitic argillite and recrystallized chert hosts small, commonly fault-bounded masses of metamorphosed and deformed gabbro and talc-serpentine schist. The latter unit is believed to have been originally emplaced as peridotite and/or pyroxenite.

The North Fork showing consists of four stratabound lenses or beds of massive and banded sulphides. The stratigraphically lowest lens ranges from 0.8 to 1.2 metres thick and comprises predominantly massive, medium-grained pyrite with minor chalcopyrite and sphalerite near the base and sphalerite-pyrite and chalcopyrite bands at the top. Chalcopyrite is associated with pyrite and sphalerite, but is concentrated in fractures which are oriented at right angles to the long axis of the lens. A 0.8-metre wide sample across the lens assayed 3.72 per cent copper, 1.41 per cent zinc, 48.0 grams per tonne silver and 0.35 gram per tonne gold (Assessment Report 14001).

Three thin (less than 30-centimetre wide), conformable and discontinuous massive sulphide lenses occur in the hangingwall of the main lens. These lenses comprise medium-grained pyrite-pyrrhotite, chalcopyrite and minor sphalerite and are not internally banded.

There is some question as to whether a distinct stringer sulphide zone and attendant disconformable alteration zone adjacent to the massive lens has been located. A lack of such zones would suggest that the North Fork occurrence may be a distal exhalative deposit.

Although massive sulphide mineralization is restricted to distinct lenses, the host biotite-quartz schist contains up to 25 per cent disseminated pyrite and minor chalcopyrite. A 0.9-metre wide sample across a pyritic zone adjacent to the main lens assayed 1.78 per cent copper, 0.27 per cent zinc, 23.5 grams per tonne silver and 0.28 gram per tonne gold (Assessment Report 14001).

Drilling undertaken to date has defined the extent of the massive sulphide lens to a depth of approximately 250 metres downplunge from the surface showing. Here, a 2.16-metre interval graded 4.82 per cent copper, 0.46 per cent zinc, 19.94 grams per tonne silver and 0.17 gram per tonne gold. Testing further downplunge failed to intersect massive sulphide mineralization. The best drill assay has come from 1982 hole DDH 1, collared 50 metres west of the main sulphide lens. Here, a three-metre interval from 63 to 66 metres averaged 2.04 per cent copper, 0.98 per cent zinc and 9.17 grams per tonne silver (Assessment Report 10797).

In 1987, drilling yielded intercepts of 1.09, 3.67 and 4.82 per cent copper, 2.57, 0.90 and 0.46 per cent zinc, 13.25, 17.00 and 19.94 grams per tonne silver with 0.07, 0.21 and 0.17 gram per tonne gold over 1.8, 1.9 and 2.2 metres, respectively in holes 87-1, -2 and -4 (Price, B.J. (2009-10-15): Technical Report – Krof Massive Sulphide Prospect).

Work History

The occurrence was first identified in 1981 by prospectors. A ground electromagnetic and self potential survey was also completed during this time. In 1982, Orbex Minerals Ltd. completed a program of geochemical sampling, geological mapping and four diamond drill holes, totalling 376.5 metres. In 1985, Falconbridge Copper completed a program of geological mapping and sampling. In 1987 and 1988, Minnova completed a further seven diamond drill holes, totalling 1397.1 metres.

In 2001, the Krof property was staked by KGE Management Ltd. and John Chapman. In 2006, a program of geological mapping, geochemical sampling and an airborne geophysical survey were completed. In 2007 and 2008, Nomad Ventures Inc. examined the area as the Krof property and completed a 275 line-kilometre airborne geophysical survey and minor geochemical (soil and rock) sampling.