38 B GEOLOGICAL SURVEY OF CANADA

600 feet below Camp Robertson, the distance by trail being one mile and a
half.

The broken character of many of the rocks along this part of the stream,
which probably affects the best section across the coal-measures in the
vicinity of this camp, together with the exposures of igneous rocks in as-
sociation, shows that the ground in the vicinity must be greatly disturbed.
This disturbance is also seen at the outcrop of the Robertson seams neir
the camp, where the coal appears to be cut off sharply on the southwest by
a fault, and is tilted on edge along the contact for some yards. The same
tilted and crushed character in the coal bed is seen in the tunnel at the
eastern limit of the coal outcrop.

Between Camps Robertson and Wilson but few rocks show on the trail.
On the crest of the ridge north of the former an outcrop of grey saad-
stone is seen, but with this exception nothing was observed until the top of
the next ridge between the east branch of the Yakoun and Wilson camp
was reached. Here, in the bed of a small brook, igneous rocks, apparently
of the underlying series, are exposed, and seem to indicate that s ‘livisicn
exists between the seams of the two camps. On a brook that crosses the
trail a short distance north of the half-way camp on lot 18, township VI,
however, good exposures of sandstone and shale appear. These streams
were traversed for a distance of two miles or more east of the trail, until
the banks of the stream became low, and for a mile west of the trail. This
stream was named Threemile creek. West of the trail on this creek fre-
quent exposures of sandstone, shale, and conglomerate occur, associated
with green diabase and hard red-brown felsitie rock. The dips vary from
north to north 70° W. < 10°-30°. The igneous rocks are well exposed for
about half a mile, but above this on the stream the sandstones are more
regular and have a dip of N. 20° E. <10°.

From the notes of survey of that portion east of the trail the rocks are,
for the most part, sandstone with fine conglomerate; an occasional dyke of
voleanic rock cuts these, but is rarely seen. The dips are usually low,
ranging from 10 to 20 degrees. For the first mile these are a few degrees
west of north, but lower on the stream the prevailing dip is northeasterly.

About twenty-four chains east of the trail, sandstone, with bands of fine
conglomerate, contain particles of coal up to an inch in size, but no out-
crops of coal veins were seen in the distance traversed. The formation in

this direction appears to be fairly uniform, and local disturbances are rare.

The principal coal outcrops in this area are seen on Wilson creek, about
three-fourths of a mile east of its forks with the Yakoun river.