The region is underlain by (?)Hadrynian to Paleozoic Snowshoe Group rocks, which occur within the Barkerville Terrane of south-central British Columbia. These metasedimentary rocks consist primarily of marble, quartzite and phyllite which in the area of the Spitfire showing comprise the Downey succession (informal). 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.
A zone of quartz veining about 150 metres long by 100 metres wide occurs within the quartzite. The quartz veins occur in groups of individual veins 0.6 to 0.9 metre apart. Veins in this zone strike at about 050 degrees, are generally vertical and range in width up to about 15 centimetres. While pyrite occurs within all the veins, gold is present only in some.
In 2003, samples (162812 and 162813) of pyritic concentrate assayed 2.725 and 3.295 grams per tonne gold (Brown, J. (2009-01-28): Technical Report on the 2000-2008 Exploration Programs on the Golden Cariboo Project).
The Gisco and Spitfire are two of a large group of recorded claims that once blanketed southern Antler Mountain and northwestern Nugget Mountain from Sawflat Creek to Wolf Creek. The claims were held by Canyon Cariboo Gold Mines Limited and included the Noranda, Zone, Lode, Pittman, and Norex groups in addition to the Gisco and Spitfire. All except some of the Noranda and Lode groups had lapsed or been transferred by January, 1955, when only nine claims were in good standing. The Spitfire group of nine located claims are on the west side of Antler Creek between Wolf Creek and the head of California Gulch. In 1946, E.S. Dowsett prospected these claims and discovered the quartz vein zone lying 213 to 274 metres above the China Creek cabin and on the north side of Wolf Creek. The veins are stripped for lengths of about 6 metres and the greatest exposed width of any vein is 15 centimetres. Of the numerous veins found and partly stripped, possibly one-half contain fine flour gold that may be panned from the weathered exposures. In 1994, Pacific Mariner Exploration Ltd. conducted an exploration program over their Antler Creek property which covers the Spitfire showing. Geochemical sampling consisted of 13 stream sediments, 10 heavy minerals, 99 soils and 26 rock chips, in addition to 2.8 kilometres of magnetometer and 1.9 kilometres of EM-16 surveying. During 2000 through 2008, Golden Cariboo Resources Ltd. completed programs of prospecting, geological mapping, geochemical (rock, soil, moss and stream sediment) sampling, ground magnetic and self potential surveys, trenching and 60 diamond drill holes, totalling 28,710.0 metres on the area as the Golden Cariboo property. A complete summary of exploration programs can be found at the Cariboo Hudson (MINFILE 093A 091) occurrence.
