At the Hecate Mountain occurrence, a 250 metre wide band of limestone of the Upper Triassic Vancouver Group, Quatsino Formation extends for 5 kilometres southwest from Handy Creek across the southeast flank of Hecate Mountain to Alberni Inlet, 27 kilometres south-southwest of Port Alberni. Bedding near the southwest end of the band strikes 012 degrees and dips 40 degrees west. Near its centre, the band is segmented by a crossfault. The northeast end of the band is also truncated by a fault. The unit is underlain by andesites and basalts of the Upper Triassic Vancouver Group, Karmutsen Formation and overlain by volcanics and sediments of the Lower Jurassic Bonanza Group.