The Alexander Creek North phosphate and flagstone prospect is located in the headwaters of Alexander and Grave creeks, approximately 14 kilometres northeast of Sparwood.

Regionally, the area is underlain by a series of generally north-trending sedimentary rocks including dolomitic carbonate rocks of the Mississippian Etherington, Mount Head and Livingstone Formations (Rundle Group) and Pennsylvanian to Permian Rocky Mountain Group, fine clastic sedimentary rocks of the Triassic Spray River Group, undivided sedimentary rocks of the Jurassic Fernie Formation and undivided sedimentary rocks of the Jurassic to Cretaceous Kootenay Group.

The area along Alexander Creek in the eastern margin of the Fernie Basin is underlain by fine-grained sandstones and siltstones containing abundant chert layers and nodules of the Permian Ranger Canyon Formation (Ishbel Group), overlain by interbedded dolomitic siltstones and shales of the Triassic Sulphur Mountain Formation (Spray River Group), followed by shales and siltstones of the Jurassic Fernie Group. These units dip west along the east limb of a major north-trending variably plunging syncline.

Locally, a thin phosphate horizon exposed in two road cuts at the base of the Fernie Group overlies siltstone of the Sulphur Mountain Formation. A sample across 0.3 metre contained 29.4 per cent P2O5 (Open File 1987-16, page 96, sample SBB86-20A). The top and bottom of the phosphate bed were not exposed.

In 1989, samples of phosphorite from the headwaters of Grave Creek yielded values of up to 29.40 per cent P2O5, 0.115 per cent yttrium, 0.029 per cent cerium and 0.047 per cent lanthanum over 0.3 metre (sample SB86-20A; Assessment Report 19942).

Also in the phosphate occurrence area, a quarry producing landscaping (flagstone) rock from black siltstones of the Vega Member of the Triassic Sulphur Mountain Formation (Spray River Group) was active during the 2000s through 2010s. The quarry was reported to measure 88 metres long by 49 metres width by 7 metres high by 2021.

In 2023, a sample of phosphate float (Alex 9) from the flagstone quarry yielded 48.23 per cent P2O5, whereas a sample (Alex 9-6) of phosphorite from above the quarry assayed 32.29 per cent P2O5 with 0.101 per cent yttrium (Assessment Report 41343). Also at this time, other samples of phosphate-bearing rocks with greater than 20.0 per cent P2O5 and 0.09 per cent yttrium were collected along the access road up to approximately 600 metres to the north and 250 metres to the south of quarry at sites Alex 17 to Alex 29, respectively (Assessment Report 41343).

Work History

This occurrence was staked and prospected by Westrock Industries Ltd. in 1988. In 1989, Formosa Resources conducted a program of prospecting, geological mapping and rock sampling on the area immediately to the south as the High Rock 1-4 claims.

In 2006, Summit Natural Rock acquired claims in the headwaters of Grave Creek. After mechanically excavating a test pit in 2007 to confirm the quality of the rock, quarrying operations were conducted in 2008, 2009 and 2011, during which an estimated total of 3500 tonnes of rock was removed.

During 2015 through 2023, Summit Natural Rock Inc. conducted minor programs of geological mapping and rock sampling on the area as the Grave Creek property.