A 150-metre wide band of Permian limestone extends westward along the north side of Blue Nose Mountain for 3.8 kilometres, 1.5 kilometres south of Lavington and 13 kilometres east of Vernon.

The band lies within a sequence of argillite and chert of the Devonian to Triassic Harper Ranch Group. To the east and west, the band is truncated by faults that bring volcanics and gneiss in contact with the limestone. Bedding strikes 080 to 088 degrees and dips 40 to 65 degrees south.

The band is comprised of white and grey streaked, coarse-grained siliceous limestone with abundant volcanic inclusions and knots and lenses of light colored chert.

A sample of chips taken at 3.0 metre intervals for 152 metres along a road cut contained 33.8 per cent CaO, 2.66 per cent MgO, 22.39 per cent insolubles, 10.96 per cent R203, 3.36 per cent Fe203, 0.06 per cent MnO, 0.05 per cent P2O5, trace sulphur, 28.18 per cent ignition loss and 0.19 per cent water (Minister of Mines Annual Report 1961, p. 148, Sample 9).