The Rayfield copper property straddles the Rayfield River, approximately 20 kilometres east of 70-Mile House between Crater Lake and the Bonaparte River. It is readily accessible by logging road. The property also has potential as a copper prospect and has been written-up as such (see also Rayfield Copper 092P 005).
The property is underlain by several phases of a concentrically zoned syenitic to monzonitic to dioritic plutonic complex probably of Late Triassic to Early Jurassic age. The complex occurs as a window through Miocene to Pleistocene alkaline plateau basalts of the Chilcotin Group which blanket much of the Cariboo Plateau. The core of the complex consists of leucosyenite composed almost entirely of alkalai feldspars with 1 to 3 per cent amphibole and trace amounts of white mica, magnetite and quartz (Assessment Report 2135). Syenite pegmatite dykes are common with feldspar comprising more than 95 per cent of the rock. Other less common syenite pegmatites contain minor amphibole minerals, less common nepheline and rare quartz. Visible low-grade copper mineralisation is widespread at a grade of between 0.05 per cent and 0.1 per cent copper over an area of approximately 600 by 2500 metres. It is mainly bornite and chalcopyrite, largely altered to malachite, and occurrs in feldspar (alteration ?) veinlets and fracture fillings and as disseminations replacing mafic minerals. The most widespread veinlet set is sheeted, trending NNW, dipping 40 to 60 degrees west. Widespread low-grade sulphide and oxide mineralisation is comprised of chalcopyrite, bornite, chalcocite, cuprite, native copper, hematite and malachite, but no iron sulphides. Trace amounts of bornite are found disseminated as blebs up to 3 millimetres in size in some of the syenite pegmatite dikes.
The earliest recorded work on the property was by Kennco Explorations (Western) Limited in 1963 on the Pat Group of claims, when programs of geological mapping and geochemical sampling (soil and stream sediments) were completed (Assessment Report 528). In 1966, COMINCO Limited (Assessment Report 859) completed a program of soil geochemical sampling (800 samples with analyses for copper, lead and zinc) and magnetometer surveying on the I.D.S. 1 to 16 claims located adjacent to the Pat Group. Mr. C. Dansey restaked the property as the BD claims and undertook a program of bulldozer trenching, subsequently optioning the property to Amax Exploration Inc. Between 1968 and 1970, Amax Exploration Inc. completed programs of geological mapping, soil sampling (approximately 1230 samples), magnetometer and induced polarisation surveys and drilled 31 percussion drill holes (1749 metres), the best result being 0.42% Cu across 6.1 metres. In 1989, the Rayfield 1 to 7 group of claims were staked by The Vernon Exploration Group and optioned to Brenda Mines Limited who completed a program of induced polarisation (36 kilometres) and diamond drilling (1140.9 metres in 8 holes). The highest results were from hole 6 which returned 1285 ppm Cu and 35 ppb Au over 164 metres.