The Parsons Creek occurrence is comprised of a folded band of impure limestone of the Upper Triassic Vancouver Group, Quatsino Formation extends for 6 kilometres northwest from Coleman Creek across Parsons Creek to Alberni Inlet. Bedding strikes 128 to 175 degrees and dips 30 to 50 degrees southwest. The band is underlain by basalts of the Upper Triassic Vancouver Group, Karmutsen Formation and Lower Jurassic Bonanza Group volcanics.