98
Peace River Valley, Cache Creek to Alces River

On the north side of Peace River, at the mouth, and east, of Cache
Creek, the Dunvegan formation is exposed in the higher parts of the cliffs
where it overlies dark shales at the top of the Fort St. John group. A
short distance downstream the outcrop of the Dunvegan recedes from
the cliffs overlooking the river, and only the Fort St. John shales are
exposed. It reappears in high banks and hills on the north side of the river
near the mouth of Alces River, and to the east rapidly descends on the
valley sides and forms low sandstone cliffs near river level.

The Dunvegan formation, southeast of Alces River and in the Pouce
Coupé Valley has been described in several reports. In the latest, that
of Gleddie (1949), it is said to be about 650 feet thick and to consist of
sandstone and shale with a little coal, mostly of non-marine, but partly
also of brackish water and marine, origin. Overlying sandstone and shale,
including the Doe Creek and Pouce Coupé sandstones, are placed in the
Kaskapau formation.

Fort St. John to Indian Creek

Hage (1944) has studied the Dunvegan formation from Fort St. John
to Indian Creek, along the Alaska Highway (See Plate VIII A). Here
are “‘fine- to coarse-grained, grey, brown-weathering, crossbedded sand-
stones interbedded with grey, brown-weathering shale. Thin coal seams
are present, and small fragments of carbonaceous material are common
along bedding planes. Lenses and beds of pebble-conglomerate are com-
monly associated with the coarser sandstone beds”.

Along the east side of Charlie Lake, massive, medium- to coarse-
grained, feldspathic sandstone, in beds up to 20 feet thick and containing
ironstone concretions up to 4 inches in diameter, is exposed in cliffs 75 feet
high. Hage (1944) states:

“A section about 350 feet thick exposed south of Trutch Creek and 5
miles east of the Highway is composed of four thick sandstone beds sepa-
rated by interbedded shale and sandstone. The upper sandstone bed is
overlain by 50 feet of pebble-conglomerate.

“Another section, east of Indian Creek... .. is quite similar to that
south of Trutch Creek. A section, 82 feet thick, of medium- to coarse-
grained sandstone containing a few thin beds of pebble-conglomerate, is
also exposed..... along the scarp [2 miles south of Suicide Hill]. On
Suicide Hill..... a 100-foot section exposed by the road-cut consists of
medium-grained sandstone beds interbedded with sandy shale that con-
tains a 3-inch seam of coal. This section underlies the thick coarse-grained
sandstone [2 miles south of this hill]. Along the Highway northwest from
Charlie Lake and at elevations higher than the outcrops east of the lake, are
outcrops of dark grey and light grey shale interbedded with fine-grained,
soft sandstone beds. Most of the shale has specks of carbonaceous material.
No fossils were found in any of these outcrops. They are believed to
represent parts of the Dunvegan formation but may be younger”.