The Dorothy Group is underlain by Lower Jurassic Hazelton Group volcanics comprised of andesite, tuff and flow breccia. A rusty, manganese stained shear zone in the volcanics, striking 305 degrees and dipping southwest approximately 58 degrees, hosts mineralized veinlets. Mineralization consists of galena, sphalerite, chalco- pyrite and tetrahedrite. Chalcopyrite with tetrahedrite veinlets crosscut the galena-sphalerite veins. Several arsenopyrite-rich, arsenic stained lenses were noted locally with galena-pyrite- sphalerite-chalcopyrite seams and stringers.

A sample across the shear zone, collected by D. Lay in 1931 assayed 3.4 grams per tonne gold, 8.6 grams per tonne silver and 3.4 per cent zinc (Minister of Mines Annual Report 1931, page 73). In 1985, a dump grab sample with galena-pyrite-sphalerite assayed 7.9 grams per tonne gold, 61.4 grams per tonne silver, 2.09 per cent lead, 1.42 per cent zinc, and 0.02 per cent copper. An arsenopyrite- rich sample assayed 9.0 grams per tonne gold and 26.05 grams per tonne silver (Assessment Report 15140).