The OH 1 lead-silver occurrence is located on a small tributary of the Frog River, approximately 6 kilometres east of Lamarque Pass and 21 kilometres south of the southern end of Denetiah Lake in the Cassiar Mountains (Assessment Report 3214, Maps 1A, 2).

Regionally, the area is underlain by a variety of Upper Proterozoic to Cambro-Ordovician rocks belonging to the Cassiar terrane of the Omineca Belt (Geological Survey of Canada Maps 42-1962, 1712A, 1713A). The rocks, most of which belong to the Ingenika Group, have been metamorphosed to greenschist grade and generally consist of calcareous and non-calcareous phyllites, schist, micaceous quartzite, limestone, marble, greenstone and pegmatite. Bedding and foliation range in strike from 270 to 320 degrees, and dip from 20 to 70 degrees north to northeast. A few kilometres to the southwest a complex of intrusive and metamorphic rocks are exposed, marking the margin of the middle Cretaceous Thudaka Batholith, possibly a faulted segment of the larger Cassiar Batholith, in contact with undivided volcanic rocks of the Upper Triassic Shonektaw Formation (Takla Group; Assessment Report 3214; Geological Survey of Canada Paper 77-1A).

Locally, the area is underlain by phyllites and contains at least two outcrops of mineralized quartz veins, located approximately 375 metres apart. Galena is finely disseminated in the quartz, forming up to 2 per cent of the hostrock. Loose blocks of quartz in the area contain up to 60 per cent massive galena with common arsenopyrite and reportedly visible gold.

Work History

In 1970, Conwest Exploration Company Ltd. completed a program of prospecting, geological mapping and geochemical (rock and soil) sampling on the area as the OH claims. Four mineralized quartz float samples (4846, 18678, 18679 and 18680) yielded from 0.63 to 1.25 grams per tonne gold, 634 to 3470 grams per tonne silver, and 7.50 to 40.0 per cent lead (Assessment Report 3214).