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were reduced to a subdued topography and a rather rapid
subsidence initiated the Upper Cretaceous sedimentation.

This region at the beginning of the Upper Cretaceous epoch
consisted of a land of moderate relief intersected by a number of
bays and estuaries in which marine sediments were being
deposited. The variation in the material of the sediments, their
rapid lateral and vertical gradation, and their similarity to
directly underlying terranes show that the Cretaceous rocks were
rapidly accumulated in great part in localized basins. After
the initial Cretaceous sinking the sediments rapidly filled up the
marine depressions, and shallow water conditions favourable for
coal accumulation prevailed. These conditions appear to have
been wide, shallow estuaries bordering land masses on the west,
and deepening into true marine basins on the east. After the
coal beds had accumulated, the interrupted sinking continued;
and the massive fine-grained sandstones of the upper Haida
were accumulated under quieter, more widespread conditions
than had previously prevailed. These conditions were followed
by a period during which rapid sedimentation just balanced
sinking, and the Honna conglomerate was formed. The Skide-
gate formation represents a time of accumulation of variable
sediments made up for the most part of fine sand or mud; and
these beds form the last record of Cretaceous sedimentation.

The general orogenic disturbance which affected the whole
Cordilleran region at the close of the Cretaceous period, the
Laramide revolution, folded and upraised the rocks of the
district under consideration, without much deformation, except
locally; and following this uplift, the Cretaceous sediments were
largely stripped from the underlying rocks, remaining only in
synclinal basins protected by walls of the older, more resistant
formations. The land surface at this time may have been
fairly even, as the accordance of level of flat-topped ridges over
considerable areas indicates conditions of this sort.

After this interval of erosion, and perhaps in part while the
Cretaceous rocks were being folded, dacite dykes, and andesite
dykes and sills were injected extensively. The main injection
probably took place in the Eocene and there are no evidences of
extrusive rocks having been formed in this epoch. In the