The Big Valley occurrence is located on the south side of the Cariboo River, approximately 2 kilometres west of its confluence with Spanish Creek.

The area is within the Quesnel terrane of the Intermontane Belt near its eastern margin, adjacent to the Precambrian to Paleozoic rocks of the Omineca terrane. The dominant lithologies comprise red-brown weathering phyllite, grey siltstone and interbedded felsic tuffs, which form the lowermost part of the Upper Triassic to Lower Jurassic Nicola Group. Formerly referred to as "black phyllite", this unit has been thrust onto the older rocks of the Omineca terrane, with which it has been deformed and metamorphosed, probably during the Middle to Late Jurassic.

Locally, a black phyllite and/or schistose argillite hosts a zone of phyllic-kaolinitic alteration over 40 metres in length with oxidized quartz veins. The veins vary from 0.2 to 5.0 metres in width. Mineralization consists of disseminated to massive galena mineralization. In 1987, a sample (638) assayed 3.35 grams per tonne gold, 339 grams per tonne silver, 18.90 per cent lead and 26.60 per cent zinc (Assessment Report 17103).

Work History

In 1967, a program of regional prospecting and sampling was completed by the Keweenaw Sydnicate. During 1981 through 1984, Apex Energy completed programs of airborne and ground geophysical surveys, prospecting, geological mapping and soil sampling on the area as the Nov 1-3 claims. During 1984 through 1986, Mt. Calvery Resources completed programs of geological mapping, prospecting, trenching and geochemical sampling on the area. In 1987, Malcom Resources completed a program of soil sampling, prospecting and trenching on the area. In 2019 and 2020, KORE Mining Ltd. completed programs of prospecting and geochemical (rock and soil) sampling on the area as part of the South Cariboo property.