The Dorlon occurrence is located approximately 600 metres southwest of the Junction of Kains Creek and the Nahwitti River.
Regionally, the area is underlain by northwest-trending belts of basaltic volcanics and carbonate sedimentary rocks of the Upper Triassic Karmutsen and Quatsino formations (Vancouver Group) and mafic volcanics and sediments of the Upper Triassic to Lower Jurassic Bonanza Group (Holberg volcanic unit, Nahwitti River wacke and Parson Bay Formation). These volcanic and sedimentary rocks have been intruded by granodioritic rocks of the Early to Middle Jurassic Island Plutonic Suite.
Locally, stringers of black sphalerite containing rare specks of galena and carrying gold values are present in silicified limestone of the Quatsino Formation. Andesites and argillites of the Bonanza Group are found to the south. A body of monzonite is in contact with both the Quatsino and Bonanza rocks. The sphalerite stringers are up to 0.5 metre wide and 6.0 metres long, strike to the north and dip vertically. A 1.5-metre wide felsite dike striking northwest and dipping vertically is exposed adjacent to the stringers.
In 1930, samples were reported to have yielded from 33.6 to 35.6 per cent zinc, 18.5 to 32.1 grams per tonne gold and 27.4 to 68.4 grams per tonne silver (Assessment Report 8944).
In 1966, a 0.61-metre wide chip sample (3019) assayed 19.2 grams per tonne gold, 24.0 grams per tonne silver and 28.35 per cent zinc, whereas a grab sample assayed 35.6 per cent zinc, 68.4 grams per tonne silver and 32.1 grams per tonne gold (Assessment Report 870).
In 1972, a chip sample assayed 6.40 per cent zinc and 29.4 grams per tonne silver over 0.6 metre (Assessment Report 4180). Drilling at this time was reported to have yielded up to 0.87 per cent copper, 15.0 grams per tonne silver and 0.44 gram per tonne gold over 1.95 metres in hole NLR-1 (Assessment Report 17393).
In 1981, a chip sample (JR 3/10) of marmatite assayed 0.204 per cent cadmium, 0.212 per cent copper, 36.02 per cent zinc, 17.1 grams per tonne silver and 13.9 grams per tonne gold (Assessment Report 8944).
Two other zones of mineralization, referred to as the Nose and Shaft zones, are located 70 metres south and 150 metres southeast, respectively, of the original Dorlon occurrence.
The Nose zone consists of a 0.25- to 0.75-metre wide, flat-lying zone of massive sphalerite thickened at the apex of a small fold in limestone. Epidote-chlorite alteration is associated with the mineralization. In 1988, a chip sample (Dorlon 003) across 2.0 metres assayed 4.2 grams per tonne gold and 17.37 per cent zinc (Assessment Report 17445).
The Shaft zone consists of massive sphalerite localized within a silicified breccia zone in limestone close to a contact with a siliceous (felsite?) intrusive. In 1988, a channel sample (Dorlon 002) across massive and disseminated sphalerite assayed 22.64 per cent zinc and 10.3 grams per tonne gold over 1.60 metres (Assessment Report 17445).
Silver-lead-zinc mineralization in silicified limestone is present 150 metres southwest of the Dorlon occurrence. In other areas, magnetite-chalcopyrite is associated with garnet-diopside-actinolite skarn. Pyrite, pyrrhotite, chalcopyrite and greenockite have also been reported.
In 1992, rock sampling (76247, 99405 and 99406) of a mineralized exposure located approximately 175 metres southwest of the shaft assayed up to 1.40 per cent zinc, 0.116 per cent lead, 4.4 grams per tonne silver and 0.39 gram per tonne gold (Assessment Report 22283).
The area has been explored since the early 1930s. In 1966, Giant Explorations Ltd. completed a program of geological mapping and geochemical sampling on the area as the HPH claims. During 1969 through 1972, Giant Explorations Ltd. completed programs of soil sampling, two drillholes and ground and airborne geophysical surveys on the area.
In 1981, the area was prospected as the JR claims. During 1987 through 1991, Hisway Resources Corp. completed programs of geological mapping, ground geophysical surveys, geochemical sampling and six drillholes, totalling 381.5 metres, on the area. In 1992, Cameco Corporation completed a program of rock and soil sampling, geological mapping and ground geophysical surveys on the area.
In 2017 and 2018, Precipitate Gold Ltd. completed programs of rock and soil sampling, gravity surveys and prospecting on the area as the Island Zinc property.
