The North Ridge-East showing is located approximately 99 kilometres north of McBride and 167 kilometres east-northeast of Prince George. The showing is 16 kilometres west of the British Columbia–Alberta border, in the Liard Mining Division.
The region is underlain by an assemblage of sedimentary rocks that were deposited in a continental shelf environment along the western margin of Ancestral North America. This clastic and carbonate rock sequence ranges in age from Hadrynian to Upper Cretaceous and now lies within the Foreland tectonostratigraphic division of the Canadian Cordillera. Folds and southwest-dipping, northeast-directed thrust faults are the dominant structures of the region.
At the kilometre scale, shallow- and potentially doubly-plunging folds, as well as thrust panels, juxtapose three units relevant to the phosphorite showing: the Mississippian Rundle Group (limestones, marbles, calcareous sediments); the Carboniferous to Permian Stoddart, Fantasque and Kindle formations (undivided sedimentary rocks) and the Triassic Sulphur Mountain Formation of the Spray River Group. The North Ridge-East showing, the Phosphate showing (MINFILE 093I 027) and the North Ridge showing (MINFILE 093I 024) all plot on the southwest limbs of two northeast-trending folds that expose these three units in succession, with the youngest Sulphur Mountain Formation at the fold core.
Phosphorite horizons are known from upper Paleozoic and lower Mesozoic strata in the region. In this area, phosphorite beds are present in the Lower Triassic Whistler Member of the Sulphur Mountain Formation (Spray River Group). At this locality, approximately 12 centimetres of phosphate rock overlies thin- to medium-bedded, grey argillaceous limestone and calcareous siltstone. The phosphorite horizon, black to dark brown in colour, has a nodular texture and contains abundant ammonite fossils. It is overlain by 90 centimetres of grey, silty limestone, which is, in turn, overlain by 18 centimetres of phosphatic shales and siltstones. A 16-centimetre layer of very fissile black shales overlie the phosphatic shale horizon and the sequence is capped by more grey limestones. The lower nodular and fossil-rich phosphate horizon is moderately high grade, containing approximately 22 per cent phosphorus pentoxide, whereas the upper horizon of phosphatic shales and siltstones contains between 8 and 11 per cent phosphorus pentoxide. The entire phosphatic interval in this area is only 1.2 metres thick and limestones comprise a greater portion of it than do phosphorites and phosphatic shales.
