The Spencer Creek showing is located 1.5 to 5 kilometres southeast of Alberni Inlet, 33 kilometres south of Port Alberni.

A fault-bounded mass of Upper Triassic Quatsino Formation, Vancouver Group limestone, averaging 600 metres in width, extends northwest for 3.5 kilometres. The mass is bounded to the northeast by andesite of the Upper Triassic Karmutsen Formation (Vancouver Group) and to the southwest by dacite of the Lower Jurassic Bonanza Group. Two small fault-bounded volcanic masses lie within the deposit to the southeast. The limestone strikes 105 degrees and dips 25 degrees northeast near the central portion of the mass. The limestone is cut by a few discontinuous andesitic dykes 1.2 to 12 metres thick which mainly strike northwest and dip vertically, although a few of the narrower ones strike northwest.

The deposit consists of fine-grained, dark grey limestone containing numerous white calcite veinlets. Dolomite occurs as irregular brownish patches and as bands up to 0.3 metres thick. Irregular small lenses of black chert are present in the limestone to the south. Three chip samples taken in succession across the north end of the deposit over a total length of 290 metres averaged 55.48 per cent CaO, 0.32 per cent MgO, 0.40 per cent insolubles, 0.16 per cent R2O3, 0.09 per cent Fe2O3, 0.08 per cent MnO, 0.03 per cent P2O5, less than 0.01 per cent sulphur, 43.74 per cent ignition loss and 0.09 per cent water (Minister of Mines Annual Report 1968, page 319, Samples 1 to 3).