General Geology

Albian marine rocks on the mainland of British Columbia. Since then, however, an
early Albian form of Beudanticeras cf. breweri Anderson has been found in a
collection made by J. Usher from the Dewdney Creek formation in Princeton map-
area in southern British Columbia. Another index fossil of the Lower Albian stage,
Douvilleiceras ex gr. mammillatum (Schlotheim), was seen in a collection of
C. H. Crickmay from the Bridge River area, also in southern British Columbia. There
it apparently occurs in the upper part of the El!dorado group. These widely scattered
occurrences of Lower Albian fossils suggest that the Haida sea may have covered
considerable parts of southern, central and northern British Columbia.

In southern British Columbia two groups of rocks have been referred to
the Albian stage of the Lower Cretaceous epoch. These are the Kingsvale and
Pasayten groups which occur in Ashcroft, Princeton and Hope map-areas. The
Pasayten group, which is mainly sedimentary rocks of continental origin, does
contain minor volcanic rocks, mainly tuffs. Age determination was made on
fossil leaves. The Kingsvale group resembles the assemblage on Swing Peak
very closely with one notable difference. The sedimentary rocks at the base of
the Kingsvale are continental in origin. The volcanic assemblage in both cases
is very similar though it may be thicker in the Kingsvale group.

The presence of volcanic rocks of similar age in such widely separated
parts of British Columbia would indicate widespread volcanism towards the
close of the Albian stage of the Lower Cretaceous epoch.

Ootsa Lake Group (12)

A series of mainly acid flows with minor amounts of basalt, andesite,
tuff, breccia, and rare conglomerate occurs in widely scattered patches in
the northeast quarter of the map-area. These rocks form the rhyolite bluffs
and ridges along Ootsa Lake and Whitesail River and many of the small
hills east of Mount Wells and Tweedsmuir and Michel Peaks. On Ootsa
Lake east of the map-area freshwater shells and fossil leaves of probable
Upper Cretaceous age were found in a conglomerate bed near the base of
the group. In Nechako River area to the east fossil leaves were found by H. W.
Tipper that are of probable Upper Oligocene age. As these rocks are exten-
sively developed along and adjacent to the shores of Ootsa Lake the term
Ootsa Lake group is proposed for them.

Flooding of the Ootsa Lake-Whitesail Lake drainage basin for the
Aluminum Company of Canada’s Kitimat project covered much of this
group, particularly the excellent outcrops along the former shores of Ootsa
Lake. Many of the beaches along the old shore of Ootsa Lake were composed

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