Glacial clays occur near Prince Rupert. Underlying bedrock is amphibolite facies metasedimentary rock of an unnamed Permo-Triassic formation.

The clay though gritty is very plastic. A sample tested worked up with 22 per cent of water to a mass that could be easily molded. Its average shrinkage is 5.1 per cent and average tensile strength is 126 pounds per square inch. The clay burns to a deep but not bright red body and would likely make a good serviceable brick (Geological Survey of Canada Memoir 47).