Several occurrences of graphite, noted on Map 12-1966, are located on Digby Island and along the west shore of Tsimpsean Peninsula. Paleozoic-Mesozoic dark argillaceous schists are chiefly thick-bedded phyllites and schists, which are locally graphitic. In zones up to 15 metres wide, the dark schist sequence is composed of intraformational conglomerate, well-bedded greywacke and pale sericite-chlorite schists.