Geologic description
In 1978, Mapco Inc. staked three claim blocks totaling 386 claims on Zarembo Island that covered much of section 36, T. 64 S., R. 82 E., and the area to the southeast of the creek that flows into the south end of Meter Bight. The claims were staked for molybdenum, fluorine, and uranium (although there is no evidence that any of these particular commodities were found in the succeeding exploration or in the samples that have been analyzed). As briefly examined in 1979 with company geologists, the mineralization then being explored was at an elevation of about 1000 feet near the creek that flows southeast across section 36 (Donald Grybeck, unpublished field observations, 1979). The mineralized exposure consisted of rusty-weathering, light green-gray felsic metavolcanic rocks with small lenses, pods, and layers up to a foot thick that contain disseminated sulfides, mainly pyrite and possibly sphalerite and chalcopyrite. The felsic metavolcanic rocks are interbedded with light gray, silicified limestone and dark gray argillite. Mapping by Karl and others (1999) indicates that much of the area of section 36 consists of the Triassic Hyd Group which hosts most of the volcanogenic massive sulfide deposits in the Duncan-Zarembo belt (Berg and Grybeck, 1980). Grab samples contained less than 5 parts per million (ppm) copper, 50 to 150 ppm lead, 200 to 11,000 ppm zinc, and 150 to 5,000 ppm barium. ATNA Resources Inc. did considerable work in the late 1980s on this prospect which that they called the 'Wally Gator' (DeLancey, 1990). They apparently concentrated their work along the creek that flows through the middle of section 36. They located three massive sulfide showings over a distance of about 800 feet. Samples from a 5-foot-thick layer in quartz-sericite schist, their most impressive mineralization, contained up to 5.5 percent zinc, 1.3 percent lead, 0.3 ounce of silver per ton, and 5.9 percent barium. Samples from a 3-foot-thick section of siliceous quartz-sericite schist contained up to 3.4 percent copper, 1.6 percent zinc, 2.0 ounces of silver per ton, and 2.1 percent barium. ATNA put down two 'Winkie'-drill holes here. The lowest mineralization was in chlorite schist that had chalcopyrite and pyrite in bands in the schist and along fractures. Samples contained up to 3.2 percent copper, and 2.4 percent zinc. They also did a geochemical soil survey in the area that identified soils with up to 1,396 parts per million (ppm) zinc and 16,960 ppm barium. Still and others (2002) also visited this location; their samples generally reflect about the same metal values as the ATNA work. |