The Volcanics (Killer Gossan) occurrence is located on the north eastern slope of Mount Sicker, approximately 11 kilometres north-northwest of Duncan.

The area is located within the Cowichan uplift and is underlain mainly by andesitic to rhyolitic volcanics of the McLaughlin Ridge Formation, Sicker Group. The local stratigraphy is disrupted by folding, faulting (pre-Triassic as well as Tertiary) and the intrusions of gabbro and diabase sills and dikes (informally known as the Mount Hall Gabbro) that are coeval with the Upper Triassic Karmutsen Formation, Vancouver Group.

Locally, porphyritic felsic flows and tuffs hosts 5 to 20 per cent pyrite with minor chalcopyrite.

In 1985 and 1986, Falconbridge Copper completed programs of geological mapping, rock sampling and a induced polarization survey, immediately to the south and east, on the Sicker and Rocky claims. In 1988 and 1989, Minnova completed programs of geochemical sampling. In 2008, Westridge Resources completed a program of airborne geophysical surveys on the area.

In 2010, Rock-Con Exploration completed a program of remote sensing in the area as a part of their Volcanics property. In 2011, Rock-Con Resources Inc. completed a program of prospecting, outcrop and float rock sampling and rock geochemistry. Sampling returned up to 1080 parts per million copper (Assessment Report 32280).