The Oy occurrence is located about 2.7 kilometres north of Tenakihi Lakes and approximately 66 kilometres north-northwest of the community of Germansen Landing.

Mineralization is hosted in Upper Triassic Takla Group andesitic and basaltic rocks in close contact with Late Triassic to Early Jurassic monzonite and diorite of the Tenakihi Intrusive Complex. Chalcopyrite occurs as fracture coatings, coarse grains in quartz veins and as minor disseminations over much of the OY (TK) property.

Chalcopyrite was most frequently seen in diorite in the south-central part of the property. For about 200 metres contour distance along the slope, epidote alteration of the diorite is evident; some hornblende is altered to biotite. Trace amounts of chalcopyrite is associated with the epidote and more rarely with large hornblende phenocrysts. Rock samples from Electrum Resources’ 1992 work yielded up to 0.078 per cent copper; the highest copper value found by Electrum was 0.29 per cent from a piece of intensely calcified Takla volcanic found as float thought to be locally derived (Assessment Report 22509).

In 1973, the Amoco Canada Petroleum Company carried out line cutting and 1:4800-scale geological mapping on their OY and DUD claims straddling Tenakihi Creek.

In 1990, Electrum Resources Ltd. staked the TK 1 and TK 2 claims and followed up with reconnaissance geological mapping and heavy mineral stream sediment sampling. In 1992, Electrum collected 19 rock samples and continued prospecting and preliminary mapping.

In 2012, C.O. Naas carried out exploration on the Cathedral property which was previously referred to as the Thane or Thane Creek property. Exploration focussed on the area around the OY showing (094C 071) and consisted of geological mapping, prospecting, and geochemical sampling. A total of 67 rock samples and 146 soil samples were collected.