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formation, where it begins to grade into the overlying Yakoun,
the sandstones contain many tufaceous and agglomeratic beds.

On the southeast end of South island are massive limestones,
light grey in colour, partly crystalline, and strongly bituminous.
They are provisionally classed with the Maude formation.

At Pillar bay, on the north coast of Graham island, and
westward from there along the coast for over 2 miles are expo-
sures of coarse conglomerate (Plates IX and X) greatly resembling
the Honna conglomerate of the Queen Charlotte series. The
beds underlie apparently conformably, sediments that are almost
certainly referable to the Maude formation, and the conglo-
merates may represent the basal beds of the latter.

Metamorphism. In the field, most of the argillites, especially
the banded flaggy varieties, have the appearance of considerably
metamorphosed rocks, and this appearance is accentuated by
the sharp local folds in which they are frequently disposed.
Under the microscope, however, the metamorphism is seen not
to have been extreme, and what has taken place seems to be
almost wholly the result of pressure unaccompanied by extensive
heating or hydrothermal action. Muscovite, chlorite, and
calcite, with, perhaps, in one instance, recrystallized feldspar,
are the only minerals whose origin is directly traceable to met-
amorphic processes, and muscovite is not largely developed.
The presence of flattened, though otherwise well preserved
fossils indicates simple pressure unaccompanied by shearing,
except locally, and this static pressure best explains the compact-
ness of the rocks, their fissility along bedding planes, and the
slight lamination apart from bedding, but parallel to it, observed
in some thin sections.

The thicker and coarser beds at the top of the formation,
though thoroughly indurated and hardened, lack the metamor-
phosed appearance of the finer, flaggy argillites.

Structure-—Internal. The Maude formation has been
folded considerably on the whole, and in many cases severely
in detail. The general strike of the formation is about north
30 degrees west. The dips are usually high, few under 30 de-
grees, and generally between 45 degrees and vertical. Localized,
recurrent zones are very severely folded and contorted, twisted,

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