This occurrence consists of float of gabbro, gabbronorite, pyroxenite, olivine melagabbro, and dunite (W.T. Ellis, oral communication, 2001). The rocks are variably serpentinized, and some contain as much as 8 percent sulfide, chiefly in pyrrhotite and chalcopyrite. A sample of sulfide-bearing gabbro contained 0.18 percent nickel, 0.05 percent copper, 46 parts per billion (ppb) palladium, and 15 ppb platinum (W.T. Ellis, oral communication, 2001). Another sample of coarse-grained pyroxenite with 8 percent pyrrhotite and minor chalcopyrite contained 0.12 percent nickel, 0.07 percent copper, 22 ppb palladium, and 35 ppb platinum.The bedrock source of the float is the Tangle ultramafic-mafic intrusive complex of Late Triassic age, which may be a lopolithic feeder of the Nikolai basalt flows of the Wrangellia Terrane (W.T. Ellis, oral communication, 2001). The Tangle complex is a north-dipping layered intrusion of dunite, peridotite, and gabbro that varies from less than 2,000 feet thick to more than 4,000 feet thick and extends for more than 12 miles in length (W.T. Ellis, oral communication, 2001). The complex intrudes Tangle Formation of Permian age (Nokleberg and others, 1991). It may connect with the Fish Lake complex at depth below the Amphitheater synform. Magmatic mineralization is synchronous with emplacement of Tangle complex, which is part of a 120-mile-long belt of mafic-ultramafic and associated rocks in the east-central Alaska Range.