83

Virtually the whole of the east coast, and the north coast
from Rose spit to Masset inlet, present a smooth shore, with
shallow water off shore. This is caused by the wearing action
of the waves on the soft Tertiary and Pleistocene rocks of this
part of the island. The dangerous bar extending northward
from Moresby island across the entrance of Skidegate inlet is
caused by a northward set of the tides, aided by strong south-
east gales that frequently sweep up Hecate straits. The low
and dangerous Rose spit, the northeastern extremity of Graham
island, famed in Haida legend, is caused by the meeting of
currents sweeping northward along the east coast and eastward
along the north coast.

The shores of Skidegate inlet and the islands in this water-
way are steep and rock bound where they are flanked by the
massive agglomerates of the Yakoun formation; where the less
resistant sediments of the Queen Charlotte series occur the shores
are more gently sloping.

Where massive granitic rocks are found on the coast the
shores are extremely steep with the result that in many places,
especially where the rocks are glaciated, landing is difficult and
in many cases impossible.

The Masset formation, with its alternating, thick, basalt
flows and softer, pyroclastic rocks, forms a jagged coast-line, as
on the west coast of the island where the headlands are formed
of basalt flows, while softer fragmental volcanics underlie the
bays. In these bays many remarkable, even, wave-cut benches
occur, just below high tide level. One of these benches is il-
lustrated in Plate VIIIB. Caves are not infrequently formed
in the agglomerates along the coast.

The most striking single feature on the coast of Graham
island is the giant stack of conglomerate from which Pillar bay
on the north coast takes its name. This excellent example of
a wave-cut stock rears its tree crowned head to a distance of
95 feet above high water mark. It is well illustrated in Plates
IX and X.

CLIMATE.

The climate of Graham island, though varying locally, may
be described as generally mild. Extremes of heat and cold are