The Onucki occurrence is underlain by well-layered volcanic rocks of the Lower Jurassic Telkwa Formation (Hazelton Group). Reddish brown coloured basalts are the most abundant rock type and comprise massive flows, breccia, tuffs and fragmentals. Three areas have been identified within the central part of the property which contains copper mineralization. These are the Pipe, Onucki and Bragg Lake zones.

The Onucki showing presents as a spectacular yellowish-red gossan located on the south-east edge of “Franks Peak". The zone is marked by a series of vertically dipping, westerly striking tabular units with individual members measuring up to several meters in width. These are composed of a siliceously altered fragmental (breccia?) carrying 5 to 10 per cent fine disseminate pyrite with no obvious copper minerals in specimen examined (Plates 7 and 8). Sampling in 1996 produced anomalous copper values with strong sections ranging to 1.2 per cent copper over a broad area (Assessment Report 24725, 24726).

Refer to Herd Dome (093L 177) for related details and for a common property work history.