The area of this occurrence is underlain by the Middle or Upper Triassic Nikolai Greenstone, a thick sequence of subaerial and submarine basalt flows and minor interbedded volcaniclastic sedimentary rocks, aquagene and epiclastic tuff, breccia, argillite, and radiolarian chert (Nokleberg and others, 1992).
The deposit is in a hydrothermally altered shear zone in greenstone, and consists of quartz, epidote, chalcopyrite, and an iron carbonate mineral. Weathering produces malachite- and azurite-coated float and encrustations.Glavinovich (1967) describes this occurrence as follows: 'Mineralized amygdaloidal andesite occurs in talus. Bornite, malachite and microscopic native copper associated with quartz pods occur in the andesite. The small quartz pods appear to have formed by replacement of the andesite. Bornite is later than the quartz and may, in part, be replacing it. Some of the strongly epidotized rock (greenstone) contains splashes of bornite, chalcocite (?) and malachite along fracture surfaces'.