The Tumannoye project is located in the northern part of the Chukotski Peninsula, at north latitude 67°37' to 67°39' and east longitude 178°04' to 178°08', in the Ilutin administrative area of Chukotka. The project is located on a Class II Egvekinot-Iultin motorway, 199km to the east of the seaport of Egvekinot. The nearest settlement, Geologichesky, is located 40km to the west. There is a 29.3MW thermal power station in Ekveginot and an 110kW power line following the Egvekinot-Iultin motorway.
The Tumannoye gold project, comprising approximately 19km2 has seen 128,000m3 of excavation and 15,771m of core drilling. The host rocks are Triassic sediments and Cretaceous granodiorites, dikes of earlier-cretaceous lamprophyres, granite-porphyries, late-cretaceous granite-porphyries, diorite-porphyrite, andesites, basalts and trachydolerites. The structures containing the gold-sulfidic mineralization are related to brecciation, collapse features and metasomatic alteration zones. The gold mineralization occurs in two forms -- tabular deposits of interspersed pyrite-arsenopyrite in metasomatically altered terrigenous-carbonaceous bodies and, to a lesser extent, as arsenopyrite-quartz stringers in mineralized dikes of granite porphyry.
Gold mineralization is reported to be associated with arsenopyrite and carbonaceous material. Also associated with the mineralization are varying amounts of antimonite, sphalerite, galena and chalcopyrite. Gold content ranges from 0.5g/t up to 111g/t, reportedly averaging 5 to 12g/t. Silver is reported at relatively low concentrations in samples. A zone of partial oxidation exists near the present ground surface.
Drilling has intersected mineralized zones up to 350m in vertical depth, with projections exceeding 400m. Some 15 separate zones (targets) have been identified in the prospect. Mineralized bodies reportedly range from 0.4m to 7.5m in thickness and from 50m to 400m along strike.
A historical resource estimate for the Tumannoye deposit by Russian investigators as at July 9, 1995 was 3.6 million tonnes at a gold grade of 7.1g/t.
