A 300 metre wide band of limestone of the Upper Triassic Quatsino Formation (Vancouver Group) extends westward from Rupert Inlet to Holberg Inlet for 2.5 kilometres, just north of Hankin Point, 16 kilometres south-southwest of Port Hardy. Underlying porphyritic basalts of the Upper Triassic Karmutsen Formation (Vancouver Group) outcrop along the southern margin of the band. To the north the limestone is in fault contact with clastic sediments of the Lower Cretaceous Queen Charlotte Group. The limestone appears to be dipping northward.

The band is comprised of light to dark grey limestone with numerous irregular masses and lenses of chert, especially along the band's northern margin. A few dykes intrude the limestone. A 91 metre long chip sample taken across the band at its west end contained 54.26 per cent CaO, 1.01 per cent MgO, 0.60 per cent insolubles, 0.42 per cent R2O3, 0.06 per cent Fe2O3, 0.019 per cent MnO, 0.02 per cent P2O5, less than 0.01 per cent sulphur and 43.77 per cent ignition loss (Minister of Mines Annual Report 1968, p. 318, Sample 3). A sample of chips taken across the east end of the band over a length of 122 metres contained 54.09 per cent CaO, 1.21 per cent MgO, 0.53 per cent insolubles, 0.40 per cent R2O3, 0.09 per cent Fe2O3, 0.018 per cent MnO, 0.01 per cent P2O5, 0.01 per cent sulphur and 43.81 per cent ignition loss (Minister of Mines Annual Report 1968, p. 318, Sample 4).