The South Copper prospect is 750 metres south-southeast of the summit of Boulder Mountain, 1.4 kilometres north of Lockie (Boulder) Creek and 6.5 kilometres north-northwest of Tulameen.
Boulder Mountain is underlain by andesitic to locally dacitic flows and pyroclastic volcanics of the Upper Triassic Nicola Group. These rocks are unconformably overlain along the west flank of the mountain, in the headwaters of Lockie Creek, by felsic to intermediate volcanics of the middle to Upper Cretaceous Spences Bridge Group. The Nicola Group rocks strike north, dip west and are regionally metamorphosed up to greenschist facies.
The deposit consists of a shallow dipping, undulating sulphide horizon, possibly of volcanogenic origin, hosted in andesitic fragmental volcanics. The horizon strikes 131 to 154 degrees and dips 10 to 30 degrees west, parallel to flow banding in the volcanics. It has been traced by diamond drilling and trenching over a strike length of 150 metres and a dip length of 150 metres.
The horizon consists of a zone of pyritized, chloritized, silicified, bleached and sheared andesite (greenstone), containing 2 to 20-centimetre wide stratabound to crosscutting chalcopyrite- pyrite rich bands and quartz-carbonate-chalcopyrite-pyrite veins. The zone is 1.0 to 3.0 metres thick, and averages 1.5 metres in thickness. A halo of hematite and epidote alteration surrounds this pyritic horizon. One drillhole analysed 1.29 per cent copper over 2.1 metres (hole 73-1, 3.7 to 5.8 metres), and a second hole, 120 metres to the north, analysed 0.21 per cent copper over 1.5 metres (hole 73-8, 2.5 to 4.0 metres) (Property File - L. Sookochoff, 1973, page 7). Four grab samples of massive sulphide mineralization assayed less than 0.10 to 0.12 gram per tonne gold, 39.1 to 87.8 grams per tonne silver and 8.36 to 20.80 per cent copper (Assessment Report 10266, Table 1, samples 81-2 to 5).
This copper deposit was first explored in 1901. The prospect remained largely undeveloped until Gold River Mines Ltd. conducted trenching and drilled 9 holes totalling 894 metres during 1972 and 1973. Since then, the deposit has been geophysically surveyed, trenched, mapped and sampled by various operators between 1980 and 1986, including most recently Abermin Corporation.