The Powerline occurrence is located near the intersection of Osborne Bay Road with the high-tension powerline, approximately 3.5 kilometres south of Crofton.
The area is underlain by volcanics of the Upper Devonian McLaughlin Ridge Formation, (Sicker Group), reported to be altered to schists in the area. Intruding the country rocks is quartz feldspar porphyry of the Late Devonian Saltspring Intrusive Suite (formerly the Saltspring Intrusions).
Locally, mafic volcanic rocks with chloritic zones host up to 7 per cent pyrite in disseminations and stringers.
In 1970, the area was explored as the Sirius claims by Canpac Minerals. In 1986 and 1987, the area was explored as the PF claims. Programs of geological mapping, prospecting and geochemical sampling were completed at this time. Grab sampling of the zone assayed 0.09 per cent copper and another similar zone, 150 metres to the west, assayed 0.07 per cent copper (Assessment Report 16029).