The CM occurrence is located about 77 kilometres southeast of the community of Dease Lake.
The area is underlain by flat lying Upper Triassic to Lower Jurassic volcanic rocks consisting of thin, red aphanitic flows, andesitic flows (possibly tuffaceous in part), conglomerate, dacite porphyry and pyroclastic beds.
The CM prospect, commonly known as the North zone, consists of chalcocite, bornite, malachite, azurite, chrysocolla and other copper oxides hosted within a shear zone that cuts a banded tuff or fine pyroclastic. The shear zone strikes 032 degrees and dips close to vertically. In 1991, a grab sample (64088) of bleached, strongly clay-altered breccia containing 5 per cent malachite and 2 per cent chalcocite analyzed 4.54 per cent copper and 60.3 grams per tonne silver (Assessment Report 22042).
One report (Assessment Report 3237) states that the mineralized zone has been traced for about 150 metres with a width varying from 1 to 7.6 metres. Another report (Property File - Chisholm, 1971) indicates a total mineralized length of more than 304 metres (open at both ends) and a mineralized width of between 6 and 12 metres. In the shear zone, altered and broken coarse brecciated fragments are surrounded by chalcocite and copper oxides.
Prior to 1972, bulldozer trenching, mapping and drilling were used to determine the extent and grade of the mineralization. The average of four 3-metre samples taken across the zone totalled 41.14 grams per tonne silver and 2.175 per cent copper (Property File - Chisholm, 1971). In 1971, four diamond-drill holes were put down and finely disseminated chalcocite and bornite were intersected in the sheared volcanic rocks accompanied by pervasive kaolinization and potassium feldspar alteration. One 6.1-metre drill interval assayed 0.39 per cent copper and 8.57 grams per tonne silver (Assessment 3237).
In 1969, Pelly Copper conducted a geological survey and first described this showing as the No. 2 zone. In 1971, Empire Metals covered this ground with the Joy, Bow, Bonus, Boldex, Pay, Sec and Sue claims. They conducted an airborne magnetic survey over greater that 10,000 hectares and completed a drilling program. Additional work in 1983 by Orsina Resources also reported carbonate and silica alteration (Assessment Report 12292). Fractures and micro-veinlets of silica form a quartz stockwork locally and in one location a pod of chalcedony was found. Rock samples analyzed at this time, although high in copper and silver, did not contain gold. The Nun claims were staked after regional exploration in 1990 discovered the Bonus (CM) (this showing) and Bold (HC) (104I 015, located 2.4 kilometres southwest) mineral occurrences. In 1991, geological mapping and sampling was performed by International Corona Corp. personnel in which 35 rock, 36 moss mat and 4 silt samples were collected.
