Geologic description
The Frost prospect consists of discontinuous pods or lenses of barite in a zone 30 feet wide and 5,000 feet long. An iron-stained silicified zone surrounds the barite and is weakly mineralized. The silicified zone dips 25 to 45 degrees W and contains disseminated sphalerite and chalcopyrite, and sulfide-bearing quartz-calcite-barite veins. These veins trend N 70 E. Bedrock consists entirely of Devonian, light- to dark-gray limestone and medium- to coarse-grained, stratified dolomite and marble (Degenhart and others, 1978).
An 8-pound sample of barite assayed 96 percent BaSO4 and 0.5 percent zinc. A sample from an 8-foot-wide, quartz-calcite-barite-sulfide vein assayed 0.49 percent copper, 13.2 percent zinc, and 20.7 percent barium. This vein could only be traced for about 10 feet along strike before disappearing under talus (Degenhart and others, 1978).
The analytical results from three rock samples (Schmidt and Allegro, 1988) follow: 1) sample T, a limestone boulder with disseminated sulfides contains 110 parts per million (ppm) arsenic, greater than 100 ppm cadmium, 230 ppm antimony, greater than 2,000 ppm zinc, 1 ppm silver, 1,000 ppm barium, 500 ppm copper, and 3000 ppm lead; 2) sample V, a boulder with quartz, fluorite, sphalerite, galena, and bornite contained 40 ppm arsenic, greater than 100 ppm cadmium, 130 ppm antimony, greater than 2,000 ppm zinc. 0.7 ppm silver, greater than 5,000 ppm barium, 500 ppm copper, 200 ppm lead and 5,00 ppm strontium; 3) sample X, a boulder with vein galena and fine-grained pyrite and sphalerite contained 80 ppm arsenic, 70 ppm cadmium, 170 ppm antimony, greater than 2,000 ppm zinc, 5 ppm silver, 1,000 ppm barium, 700 ppm copper, 5 ppm molybdenum, and 7,000 ppm lead. In 2006, NovaGold began working in the region and staked a large block of claims that covered this and other similar prospects nearby (TintinaGold Resources Inc., 2010). In 2007, NovaGold carried out extensive field work in the area emphasizing geologic mapping and geochemical sampling. They describe the Frost prospect as a northwest-trending zone about 750 meters long and 200 meters wide of sparse outcrop and abundant rubble crop of barite-sulfide-fluorite mineralization. The sulfides are mainly sphalerite, galena, bornite, and chalcopyrite. Both stratabound and crosscutting mineralization is present. Selected rock samples contain up to 30.6 percent zinc, 20.2 percent copper, and 52.5 grams of silver per tonne. |