The Centennial showing is on the northwest slopes of Little Thunder Mountain. The host is massive porphyritic andesite or basalt of the Upper Triassic Karmutsen Formation, Vancouver Group.

On the northeast side of small gully a shear zone striking 070 degrees and dipping 53 degrees south forms the hangingwall of a small zone of shearing, alteration, and mineralization. The footwall is covered and the exposed thickness is 3 metres. The zone is 6 metres long, terminating abruptly at both ends. Within the zone the rock is silicified and abundantly mineralized with chalcopyrite and pyrrhotite, both partly weathered to limonite. One report also includes the presense of magnetite and pyrite but not pyrrhotite. A grab sample assayed 8.28 per cent copper with a trace of gold and silver (Geology, Exploration and Mining in B.C. 1974).

The No.5 showing is exposed in a road cut along the east side of the north ridge of Little Thunder Mountain. Karmutsen rock is cut by a 13 centimetre wide calcite vein containing minor chalcopyrite and bornite. A 46 centimetre wide felsic dyke occurs about a metre northeast of the vein and contains sparsely disseminated chalcopyrite. For about 1.5 metres on either side of the calcite vein the rock is intensely epidotized and contains a few specks of sulphide.