The Skarn showing or Silver Mine adit is located just north of Penny Creek, about 22 kilometres southeast of Barkerville.
The geology of the region consists of dominantly metasedimentary (?)Hadrynian to Paleozoic Snowshoe Group rocks, which occur within the Barkerville Terrane of south-central British Columbia. The metasedimentary rocks consist primarily of marble, quartzite and phyllite which in the area of the Cariboo Canyon showing comprise the Downey succession (informal name). Metamorphism of the region varies from chlorite grade to sillimanite and higher. The lode gold deposits of the region occur in rocks metamorphosed no higher than greenschist facies.
The Skarn showing is underlain by quartz-sericite schist and interbedded limestone. Quartz veins and lenses occur in the limestone over a distance of about 250 metres along Penny Creek. Mineralization in the quartz veins and lenses consists of pyrite, galena, sphalerite, tetrahedrite and scheelite. Pyrite and scheelite occur, in some cases, as disseminations in wallrock. Ankerite occurs within the schist adjacent to the quartz veins. It is not, however, clear whether ankerite is a primary metamorphic mineral or the result of metasomatism associated with sulphide mineralization.
The structure mined during 1980 consists of a polymetallic quartz vein, 0.5 to 1.5 metres in width on surface, and can be traced for over 200 metres along strike. Strike varies from about 350 to 360 degrees, and the dip varies from approximately 60 to 90 degrees east. A feldspar porphyry diorite dike, 0.3 to 1.0 metre in width, subparallels the quartz vein structure, and locally contains quartz vein fragments. A 1.8 metre wide portion of the Silver Mine vein yielded 156 parts per billion gold, 233.4 grams per tonne silver, and approximately 1.1 per cent copper, 2.2 per cent lead, 1.9 per cent zinc, 0.88 per cent antimony, and 0.1 per cent tungsten (sample #76403, Assessment Report 24092). Tungsten values up to 1662 parts per million were returned from the Silver Mine structure (sample #76406, Assessment Report 24092). Several zones of alteration with quartz veins occur to the west of the Silver Mine vein; in this area, up to 8.6 grams per tonne silver with minor lead and zinc occur over a 4.0 metre width (sample #76362, Assessment Report 24092).
A well mineralized sample (#5475) taken in 1970 across 1 metre of the footwall of a vein on the Roundtop 43 and 44 claims (exact location uncertain) assayed 1.37 grams per tonne gold, 4391.27 grams per tonne silver, 4.54 per cent copper and 10.24 per cent lead; other samples were significantly lower (Property File - Coast Interior Ventures Ltd. Prospectus July, 1971). In 1980, the Coast Interior Ventures Ltd. property was operated by Chaput Logging Ltd. At this time, 61 metres of tunnelling on the Roundtop 1, 3, 43 and 44 claims was completed (Exploration in British Columbia 1980, page 311). Government documents record 172 tonnes of ore milled with 721 grams of gold, 243,385 grams of silver, 10,386 kilograms of lead, 3956 kilograms of zinc and 1072 kilograms of copper recovered.