On the east side of Effingham Inlet, about 8 kilometres up, there is a high bluff of reddish brown rock, having a compact, fine grained texture and showing no cleavage or bedding planes. The rock consists of angular grains of quartz, which are cemented together by a fine aggregate of granular material, which is almost wholly hematite. The rock is reported to be a jaspilite or impure jasper and to have possible value as a building stone.

Associated with this rock mass are intrusions of a greenish volcanic rock having a more or less amygdaloidal texture. The area is underlain by Upper Triassic intermediate to mafic rocks of the Karmutsen Formation, Vancouver Group.