156

applicable to the Graham Island deposits, for at both Camps
Robertson and Wilson, severe folding accompanied by minor
faulting has not caused anthracite to form.

Campbell’s hypothesis,! that anthracite formation is facil-
itated by the escape of gases through greater permeability of the
enclosing rocks, is no more helpful in this case; for the measures
enclosing the anthracitic coal are very dense shales, much more
impermeable than the coarser beds of Camps Robertson and
Wilson.

LIGNITE.

Location. Lignite is of widespread occurrence in the Skonun
formation, of Tertiary age. The most westerly locality where it
is reported to be in place is on Lignite creek which enters Naden
harbour near its southeast corner. Lignite has been reported
from near Parry passage, at the northwestern extremity of Gra-
ham island; but Mr. Henry Edenshaw, who is thoroughly familiar
with the district, states that the lignite found there was not in
place. It was probably carried by waves and currents from the
outcrops to the east. At Skonun and Yakan points on the north
coast of Graham island, there are several seams of lignite. On the
Mamin river entering Juskatla inlet, in the interior of the island,
Dawson? reports lignite as occurring 6 miles up stream from the
mouth. Along the east coast of the island as far south as
Spit point on Moresby island, fragments of lignite are occa-
sionally cast on the beach after storms, and are presumably torn
from submarine outcrops. Clapp’ reports having seen lignite
said to have come from the headwaters of the south branch of
the Tlell river.

Lignite of Skonun Point. At Skonun point there are
several seams of lignite which have attracted considerable atten-
tion of late years. This was the only lignite seen in place by the
writer; but, unfortunately, the tides at the time when the
locality was visited were not low enough to allow of a careful
examination being made. The following account of the occur-
rence is, therefore, taken from Clapp’s report.‘

1 Campbell, M. R., Econ. Geol. vol. 1, 1905, p. 26.

2 Dawson, G. M., Geol. Surv., Can., Rept. of Prog., 1878-79, pp. 85B-89B.
3 Clapp, C. H., Geol. Surv., Can, Sum. Rept., 1913, p. 38.

4 Ibid. p. 38.