The Discovery II showing occurs within Lower Cretaceous Gambier Group rocks of the Callaghan Creek roof pendant, one of many northwest trending volcanic and volcanic-sedimentary pendants within the southern part of the Jurassic to Tertiary Coast Plutonic Complex. Contacts between roof pendants and the surrounding plutonic rocks are sharp and, commonly, are narrow shear zones with orientations subparallel to the main foliation of the roof pendant.

The occurrence is reportedly underlain by weakly metamorphosed greenstone or schist with intercalated sedimentary units. These rocks have been cut by northwest trending shears and fault zones. The mineralization is reported to be associated with sheared greenstone and rhyodacitic dykes. Mineralization includes sphalerite, galena, chalcopyrite and hematite in crosscutting quartz veinlets, as disseminations and as massive sulphides which are locally layered parallel to the foliation.

A sample from a shear zone in andesitic greenstone assayed 0.895 gram per tonne gold, 8.3 grams per tonne silver, 0.7 per cent copper, 0.2 per cent lead and 5.4 per cent zinc (Assessment Report 16443).