The McAdam showing is located 16 kilometres east of Stewart near the southeastern margin of the Bromley Glacier. The showing was first discovered in 1965 and the area is presently being investigated for gold mineralization. The Red Mountain discovery (103P 086) is located approximately 1.5 kilometres to the northeast.
The region is underlain by sedimentary rocks of the Middle to Upper Jurassic Hazelton Group intruded by Eocene granitic Coast Plutonic Complex rocks.
The showing is underlain by thinly laminated, variably schistose and broken quartzites, crystal tuffs and siltstones which have been intruded by a coarse grained granodiorite stock. The distorted bedding trends northwest and aplitic to pegmatitic offshoot dikes are common. Evidence suggests that these rocks lie on the steep overturned east limb of a regional anticlinal structure which trends and plunges northward.
The stock is mineralized with pyrite and molybdenite as irregular fracture or grain boundary fillings and molybdenite as well shaped randomly disseminated rosettes. Pyrite and molybdenite also occur in irregular veins or lenses along several vertical north trending shear zones which transect the stock and hornfelsed sediments. The offshoot dikes contain scattered mineralization and quartzites contain minor pyrite, molybdenite and apatite. Apatite occurs as a major constituent in lenses within impure quartzites, which exhibit well preserved primary structures. The contact zone around the stock contains pink feldspar and mineralized quartz veins. Portions of the contact zone are well mineralized with molybdenite and grades are generally higher than in the stock itself. Gold is reported to be present in significant amounts in large quartz veins in the peripheral mineralized zone and in pyrite veins (Red Mountain, 103P 086). The veins also contain galena, sphalerite, pyrite, and tetrahedrite.
The stock may extend under the ice to Lost Mountain (103P 007) where several outcrops of similar granodiorite with molybdenite mineralization have been located. The Bromley Glacier is receding quite rapidly, 107 metres from 1960 to 1967, exposing more of the stock. It is possible that the granodiorite extends to the Goldslide Creek (103P 221) area and if so the stock would be 137 metres below surface. It is speculated that the porphyry and granodiorite are related.
An 8.5 metre sample from a pyritic shear zone averaged 0.23 per cent molybdenite and 8.57 grams per tonne gold (Assessment Report 1588, page 7). Resampling of core from drillhole N-5 in the granodiorite averaged 0.001 per cent molybdenite (Assessment Report 6580, page 4).