Massive sulfide boulders are sparsely distributed in the drainage of Rock Candy Creek. Follow-up work to locate their source led to the discovery of 4- to 6-inch-thick massive and disseminated, volcanogenic sulfide lenses as well as multiple, but thin, hydrothermal veins with appreciable amounts of base and precious metals. Samples contain as much as 4 percent zinc, 1.5 percent lead, 0.1 percent copper, and 1 to 2 ounces per ton silver. Lenses of massive pyrrhotite 4 to 8 inches thick were found on the north side of Rock Candy Creek in quartz-sericite schist exposed on a dip slope. The pyrrhotite contains trace sphalerite, chalcopyrite, and galena (R.A. Blakestad and others, unpublished Resource Associates of Alaska, Inc. report, 1976).This occurrence is in the Jarvis Creek Glacier subterrane of Devonian age (Nokleberg and others, 1992). This subterrane consists of a complex sequence of volcaniclastic metasedimentary rocks, predominantly of intermediate composition. The unit includes felsic and mafic metavolcanic units and metasedimentary rocks, including calcareous schist, dolomite, limestone, siltstone, quartzite, and black carbonaceous schist. The rock units are typically thin bedded, strike northwest, and dip moderately southwest. The schistosity and folds are generally parallel to the regional strike but with local exceptions (R.A. Blakestad and others, unpublished Resource Associates of Alaska, Inc. report, 1976). The metamorphosed volcanic and sedimentary rocks have been intruded by several gabbro and mafic sills and dikes and plutons of felsic to intermediate composition (R.A. Blakestad and others, unpublished Resource Associates of Alaska, Inc. report, 1976).