The Hushamu Pyrophyllite occurrence is located at an elevation of approximately 400 metres on a northeast-facing slope, southwest of Hushamu Creek and approximately 600 metres southeast of the southeast end of Hushamu Lake.
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 to felsic volcanics and sediments of the Upper Triassic to Middle 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 Lower to Middle Jurassic Island Plutonic Suite.
Locally, pyrophyllite-bearing silicified breccia has been interpreted as a volcanic centre (Geology, Exploration and Mining 1974, page 217). Additional centres are found to the northwest and are associated with the Hep (MINFILE 092L 078), Red Dog (MINFILE 092L 200) and South Knob (MINFILE 102I 013) occurrences. Similar mineralization is found to the southeast, including another pyrophyllite-bearing breccia interpreted as a volcanic centre at the Pemberton (MINFILE 092L 308) occurrence and in the vicinity of the Island Copper (MINFILE 092L 158) deposit where pyrophyllite-bearing zones are exposed in the mine workings.
The occurrence is described as a pyrophyllite-bearing silicified breccia that hosts minor disseminated pyrite and chalcopyrite. The breccia also contains sericite, clay and zeolites. The pyrophyllite is thought to be formed as a product of hydrothermal alteration during low-grade regional metamorphism (Open File 1988-19).
Work History
The area has been explored in conjunction with the nearby Hushamu (MINFILE 092L 240) copper-gold porphyry occurrence and a complete exploration history can be found there.