The Buck property, located 69 kilometres southeast of Windy Craggy, consists of 54 claim units that were staked in 1989 to cover a large brown to orange-weathering gossanous zone at the confluence of the Tkope River and Tsirku Glacier (McDougall et al., 1989).
A mineralized and altered zone approximately four kilometres long and up to three kilometre wide is exposed along a northwest-trending ridge that is bounded to the east by the Buckwell Glacier, to the south by the Tsirku Glacier and to the west by the Tkope River. Where exposed, the zone includes brecciated quartz-carbonate-altered volcanic and sedimentary rocks of possible Triassic age. Bedding, as defined by pyritiferous sediments, trends northwest and dips steeply east. Intensely deformed black argillaceous sediments and limestones that may be correlative with the lower part of the Tats group outcrop to the west of the Tkope River.
Sulphide mineral assemblages within the zone include varying proportions and concentrations of fine-grained disseminated to coarse-grained, interstitial pyrite, pyrrhotite and rare chalcopyrite. Manganese oxide coats fracture surfaces. Within the zone, intense silica flooding and development of mariposite are reported. Secondary silica is apparently present as grey chert to opaline masses rather than as veins and veinlets. The alteration assemblages suggest a high-level hydrothermal system of possible epithermal orgin. Many of the rocks within the altered zone are light coloured and are mapped as felsic volcanics but this coloration probably reflects intense silica-sericite-clay alteration rather than original rock composition.
A sample from a pyritic shear zone near the crest of the ridge apparently assayed 18.41 grams per tonne gold, 0.58 per cent copper, and 25.5 grams er tonne silver (McDougall et al., 1989). Other samples from the area contained up to 0.9 per cent copper, 0.22 per cent zinc, 4.1 grams per tonne silver, 0.23 per cent manganese, and 176 parts per million arsenic with generally low but anomalous gold values.
Additional sampling in 1990 failed to delineate any continuous zones of gold, silver or copper concentration although isolated samples returned copper values between 0.15 and 0.85 per cent and zinc values to 2.44 per cent (McDougall, 1990a). Small zones of massive to semimassive pyrite occur along northwest and northeast-trending shear zones. Northwest-trending basaltic dikes and sills up to 35 metres wide also appear to be intruded along these zones. Brecciation is apparently associated with these basaltic intrusions and narrow copper-bearing shears parallel their northeastern contacts.
