The Tumbler Ridge Phosphate (Muinok Zone) occurrence is located on Muinok Mountain, approximately 9 kilometres south-southwest of Belcourt Lake. The showing is approximately 160 kilometres east-northeast of Prince George, and 27 kilometres from the British Columbia–Alberta border.

Regionally, the area is underlain by Lower to Middle Triassic Sulphur Mountain Formation, lower Carboniferous Rundle Group and Upper Devonian Exshaw and Banff formations. These units and those surrounding are tightly and complexly folded with northwest-trending fold axes, and are juxtaposed by northeast-directed thrusting.

Locally, grey weathering dark-grey recessive siltstone, approximately 20 to 85 metres thick, of the Whistler Member of the Lower and Middle Triassic Sulphur Mountain Formation is structurally exposed. The Tumbler Ridge Phosphate occurrence is hosted within this unit, exposed as the core of a shallowly plunging fold structure.

The Muinok zone is described as varying from 2 to 10 metres wide over a 400-metre length strike length. Trench samples yielded an average grade pf 3.4 per cent phosphorus pentoxide over 7.8 metres, while narrower zones averaged 7.5 and 11.8 per cent phosphorus pentoxide over 6.0 and 4.0 metres, respectively, with spot highs of 16.0 per cent phosphorus pentoxide over 2.0 metres (trench 6) to 21 per cent phosphorus pentoxide over 1.0 metre (trench 5; Assessment Report 30718 and 34629).

Work History

The Muinok Zone was discovered in 2008, during an exploration campaign that included the collection of more than 450 samples, including 67 grab and 133 chip samples from the Muinok zone.

In 2014, J.T. Shearer conducted a program of photo-geological interpretation on the Belcourt 1-4 claims.