The area is underlain by Lower Jurassic Bonanza Group volcanics and sediments intruded by rocks of the Early to Middle Jurassic Island Plutonic Suite.

Locally, brecciated hydrothermally altered andesitic to basaltic lapilli tuff and tuff breccia of the Bonanza Group are cut by a northwest trending quartz-feldspar porphyry dyke swarm.

At the western edge of the Island Copper deposit (refer to 092L 158), the dyke is overlain by an intensely altered breccia zone up to 150 metres wide and 1000 metres long. The zone is massive greyish-tan pyrophyllite, quartz and kaolin, speckled with bright blue dumortierite. The zone appears brecciated and has a coarse, gritty texture. The alteration is due to siliceous differentiates of the quartz feldspar porphyry system permeating brecciated rocks. The brecciation and alteration are inferred to be synchronous with the brecciation and emplacement of the dyke (Exploration 1970, page 254).

A chip sample across a 15 metre exposure on the east end of the zone was analysed by the Ministry of Energy, Mines and Petroleum Resources in 1968, yielding the following values:

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                   SiO2                   83.18%
                   Al2O3                  13.36%
                   H2O > 105  Celsius      2.78%
                   -----------------------------

Spectrographic analysis indicates the presence of iron, titanium and 0.5 per cent boron (Open File 1988, page 93).

Work History

The area has been explored in conjunction with the adjacent Island Copper (MINFILE 092L 158) deposit.