black slate with a moderately well developed cleavage, black
slaty argillite, thin beds of fine, grey sandstone, and massive
light grey limestone. The limestone occurs in the other sedi-
ments as beds ranging from 5 to 200 feet in thickness. One
bed of limestone about 60 feet thick crosses Wheaton Creek and
forms the bed-rock of the falls. Another member is a belt of
green andesitic flows, which outcrops in a band 3,000 to 5,000
feet wide south of the lake towards the head of Wheaton Creek.
The andesite is intercalated with quartz mica schist and con-
tains short lenses of limestone up to 50 feet wide. The in-
cluded limestone is fine grained in places and coarsely crys-
Talline in. others.

The sedimentary rocks outcrop in two main belts. One
large area, mostly underlain by sediments, lies to the north
and north-east of Barrington's camp. Another large area ex-
tends southward from a point about 1 1/2 miles south of the
mouth of Alice Shea Creek. Both these areas (see Fig. 3) are
believed to be almost entirely underlain by the sedimentary
and volcanic succession.

Other large and small sedimentary outcrop areas are
shown on Fig. 5. There are large areas underlain by slate and
sandy sediments along the ridge top west of Wheaton Creek, on
the ridge between Alice Shea and Wheaton Creeks and on the
ridges surrounding the Philippon Creek drainage basin. Other
small areas observed, were only 50 to 100 feet wide, and too
small to show on Fig. 3. A number of these are exposed along
the bottom of Alice Shea Creek; one is about 1,500 feet wide,
the others considerably less. The lengths of many sedimentary
areas could not be seen because of the scarcity of outcrops.
However, where these sediments occur in serpentine it is be-
lieved that they are not continuous along their strike and
are completely surrounded by serpentine.

Serpentine. The most conspicuous rock exposed in lower
Wheaton Creek valley is serpentine. On a weathered surface
its colour may be light greenish-grey, yellowish-buff, green-
ish-yellow, bright yellowish-green or greenish-black. Some
weathered surfaces have a warty appearance resulting from the
resistance to weathering of small magnetite grains. In places
the serpentine is massive, in others, it is intensely sheared.
Some sheared zones in the serpentine have a spheroidal weather-
ing almost like pillow structure in lava. At one point, on
the north slope of Mt. Shea, the serpentine appears porphy-
ritic. This results from the almost complete serpentinization
of the rock, partly altered pyroxene being left as pseudo-
phenocrysts. In general, the rock, under the microscope, is
seen to be composed largely of serpentine (antigorite), and

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