A collection of fossil plants from the sandstone quarry
at mile 68 was examined by W. A. Bell of the Geological Survey, who
identified the following: Platanus latiloba Newberry, Protophyllum
undulatum Lesquereaux, Araliaecophyllum rotundiloba ? (Newberry),
Magnolia ? sp., and laurophylium sp. = ——ti—‘iS™S

- Regarding this collection Bell states that although the
florule includes very few identifiable species, it is considered to
be probably of Cenomanian (carly Upper Cretacoous) age. The col-
lection is not as complete as the one previously made by Williams
(1932), but includes the same species. The sandstone in the quarry
at mile 68 can, therefore, be said to be of the same age as the
Dunvegan formation along Peace River. Consequently, the sandstone
and shale beds that outorop along the Highway from Fort St. John to
mile 108 are either Dunvegan or younger.

Pleistocene

Deposits of glacial material of various types occur along
almost the entire route of the Highway from Fort St, John to Fort
Nelson. On the higher land the deposits are thin to absent, whereas
on the lower slopes, and especially in the valley bottoms, the
‘deposits are thick. Glacial lake clays are found in most of the -

_ larger stream valleys and boulder clay having the nature of: encund
mora ine is the characteristic deposit elsewhere.

Bedded clay deposits up to 50 feet thick are found a:
Beatton, Halfway, Minaker, and Prophet River Valleys. In most
instances they are underlain and overlain by till. The underlying
till differs from the overlying one in the composition of the con-
tained pebbles. Along the Halfway River, about 3 miles east of
Pink Mountain, and along Minaker River north of mile 155, the under~
lying till contains pobbles of quartzite and sandstone. Ona
tributary stream flowing into the Minaker from the west a 20-foot
gravel deposit underlies the glacial clay. The gravel is composed
of well-rounded pebbles of sandstone of various kinds and of chert,
limestone, light grey quartzite, and feldspar porphyry. Similar
gravel deposits were observed along Prophet River east of Klingzut
Mountain. The overlying till in all instances contains a large
percentage of pebbles and boulders of igneous and metamorphic rocks,
including various types of granite, schist, and gneiss. Along the
banks of Prophet River this boulder clay deposit is several hundred
feet thick. The lower till appears to have a source different from
the overlying one and, as the pebbles and boulders contained in it
are Similar to the rocks outcropping in the immediate vicinity to the
west, it seems reasonable to conclude that the glacier that deposited
this material moved down the valleys from that direction. The source
of the upper till containing the igneous and metamorphic pebbles and
boulders may have been the Precambrian Shield to the northeast.

The character of the surface till varies considerably at
different localities. South of Sikanni Chief River granite boulders
are present, but are not numerous; north of the river igneous
boulders are more numerous; and along Buckinghorse River and other
streams farther north they are plentiful.

The major stream valleys are pre-glacial in age.’ In
Prophet River Valley, for example, the present stream follows the
old valley very closely, and it is only here and there that it has
cut into the old river bank to expose outcroppings of the bedrock.
Because of the thick deposit of glacial material in this old drainage
channel outcrops along the present stream are few.