by the thick conglomerates of Pillar bay, on the north coast of
Graham island, the total thickness of the Maude formation may
reach 9,000 or 10,000 feet.

Structure —External—Relation to Younger Formations. The
Maude formation grades conformably into the Yakoun forma-
tion which is the upper member of the Vancouver group on
Graham island. This relation is well shown on the south shore
of Maude island, and on the opposite shore of Moresby island.
Near the centre of the south side of Maude island the rocks are
typical, well banded, fine, dense argillites, in part slaty, and are

— —_ SS ee ee

One-tenth s/ze

Geological Survey, Canada.

Figure 4. Sketch of faulted band of laminated argillites in the Maude
formation on King creek. A photograph of this same band is
given as Plate XIB.

fossiliferous. Eastward along the shore, the rocks are well
exposed. They occur in moderate folds, and are coarser and
thicker bedded. As the horizon of the Yakoun formation is
approached, tufaceous material becomes more prominent;
but the rocks are still hard, fine, and evenly bedded, and are
clearly transitional in character. Farther east massive greenish
breccias of the Yakoun volcanics form bold, precipitous cliffs.