Fresh water, diatomaceous earth is reported to occur in Dutch- man's Swamp, about 2.4 kilometres from the north end of Gabriola Island. In 1939, a small plant owned by the West Coast Silica Prod- ucts Company, was in operation processing the diatomaceous earth. The mill processed about 1.5 to 2.0 tonnes of calcined material which was stockpiled at the site.

Excavations indicated that the diatomite was a high grade de- posit, averaging from 0.9 to 1.5 metres in thickness, within a deep, elliptically shaped basin.