The RB 12 NW showing area, located 75 kilometres west of the Cassiar Highway and 10 kilometres east of the Stikine River, is underlain by andesite, basalt and trachytic flows, volcanic breccias, conglomerates and tuffs, as well as shaly metasedimentary layers and sandstones of andesitic origin. Monzonite and syenite of the Upper Triassic to Early Jurassic Copper Mountain Plutonic Suite and Early Jurassic monzodioritic to gabbroic plutons of the Texas Creek Plutonic Suite intrude the country rock in the area.

Regional mapping (as shown on MapPlace) indicates the RB 12 NW area to be mainly underlain by unnamed Upper Triassic to Lower Jurassic alkaline volcanic rocks. This unit consists of coarse pseudoleucite and pyroxene, feldspar flows and breccias interlayered with orthoclase feldspar, biotite crystal tuffs and epiclastic units, including thick polymictic volcanic conglomerate horizons. They are also in contact with Upper Triassic Stuhini rock consisting of a complex of undivided volcanic and sedimentary rocks.

In 1991, in the northwest area of the RB 12 claim of the Anuk property, a mineralized area (Zone 3) was found to consist of tuffaceous argillite and quartzose sediments with minor interbanded volcanics; these rocks gradually become more volcanic to the east. A small feldspar porphyry intrusion cuts through volcanic rocks. The intrusion contains zoned feldspar phenocrysts up to 1 centimetres.

Sampling around the contact returned significant copper (0.28 per cent copper over 3 metres) but insignificant gold values, however a float sample upslope from the contact graded 0.6 per cent copper, 0.82 gram per tonne gold and 37 grams per tonne silver (Assessment Report 22035). About 800 metres to the east of the contact samples (R05 to R10), massive pyrite mineralization over 20 centimetres with 0.28 per cent zinc (91K-05) was obtained from a shear within the sedimentary unit. Scattered between the intrusive contact zone and sample 91K-05, and south to southeast of the feldspar intrusion contact over 400 metres, 20 float samples were collected, many of which carried significant copper and gold values ranging up to 3.82 per cent copper and 9.39 grams per tonne gold (Assessment Report 22035).

Sample descriptions from Zone 3 indicate that pyrite and chalcopyrite were common but rarely bornite. Mineralization occurs along rock faces, fractures, shears, sometimes with quartz or quartz veins and as disseminations.

Refer to Anuk RB 18 for expanded geological information and a common work history.