The Lucky Boy showing is within limestone of the Lower Cambrian Laib Formation, Reeves Member which is correlative with limestone of the Badshot Formation. Several granitic stocks of the Middle to Late Jurassic Nelson Intrusions disrupt the strata. The area is underlain by a north plunging complex fold structure.
Pyrite, sphalerite and galena mineralization is controlled by steeply dipping shears, subparallel to the banding in dolomitized limestones. Veins, up to 1.3 metres wide, have been exposed but were found to be discontinuous in extent.
A drill program conducted in 1987 by Cominco Ltd. outlined two separate mineralized zones within the synclinal structure. Both zones occur at the same stratigraphic level, near the base of the Reeves Member. The host is a medium crystalline pinkish or white metadolomite.
The sulphide zone ranges in thickness between 0.3 and 5.0 metres. Within the zone, sulphides, mainly sphalerite, occur as weak disseminations with occasional patches of heavier dissemina- tions, streaks and thin bands, and in a few cases as small, nearly massive lenses. These lenses of massive sphalerite are rarely more than 0.5 metres thick. In nearly all cases the sulphide bands, streaks and lenses are parallel with the local foliation and/or bedding. The thickness and grade of the sulphides improve on the crest and in the trough of the attenuated isoclinal folds.
One of the highest assays taken from a 0.5 metre length of drill core graded 0.013 per cent lead, 4.7 per cent zinc, 1.27 grams per tonne silver and 0.0274 per cent cadmium (Assessment Report 17710).