The Sudbury Pacific showing is located just below mean sea level on Seddall Island, near Ecoole. The location is uncertain from the description given of the work done in 1917.

The area is underlain by volcanic rocks of the Lower Jurassic Bonanza Group and carbonate rocks of the Upper Triassic Quatsino Formation, Vancouver Group. These have been intruded by granitic rocks of the Early to Middle Jurassic Island Plutonic Suite.

The showing comprises small lenses of pyrrhotite and associated arsenopyrite hosted in breccia material in a fractured and fissured zone within diorite (possibly granodiorite). This zone is about 1.2 or 1.5 metres wide. The showing can be examined only at extreme low tide.

Two samples, each taken across 0.20 metre of mineralized breccia material, assayed 0.35 (sample 1) and 1.9 per cent nickel (sample 2) (Minister of Mines Annual Report 1917, page 246).