83

Beach and Spivak collected the marine pelecypods, Posidonomya
nahwist var. goodrichensis and P. nahwisi var. moberliensis in this for-
mation on an east branch of Coalbed Creek, southeast of Moosecall Lake
(See Figure 11); and on the central branch of Coalbed Creek.

Much farther west, between Pine and Peace River Valleys, on the
northeast spur of Mount McAllister, 1 mile east of Wright Lake, Mathews
(1947) has mapped the rocks of a small area as Goodrich. The beds consist
of sandstone with minor amounts of conglomerate. Northward from Peace
River Valley the sandstones of this formation are continuous with those
in the lower part of the Sikanni formation.

Cruiser Formation

The Cruiser formation lies conformably between the Goodrich and
Dunvegan formations, and is the highest formation of the Fort St. John
group in the Pine and Peace River Foothills. It consists of 800 to 900 feet
of dark shales, with some beds of sandstone. It was first named by Wicken-
den and Shaw (1943), and first applied by them to beds in the Pine River
Foothills. The formation is said to be well exposed on Cruiser Mountain,
which is the type locality of the formation.

Wickenden and Shaw describe the lower contact of the Cruiser for-
mation, as exposed on Bowlder Creek between 400 and 700 feet below the
forks. ‘‘The contact shows a change from heavy massive sandstone in
the Goodrich to dark grey shale and sandy shale of the Cruiser through
several alternating beds of sandstone and shale’. About 60 to 70 feet
of the lower part of the Cruiser are exposed.

More than 700 feet of the uppermost part of the Cruiser is exposed on a

small tributary on the south side of Pine River, ~ to 1 mile east of Young
Creek. Wickenden and Shaw measured a section there:

Top of Section Thickness

Dunvegan formation Feet
Shale and sandstone, dark and medium grey................-- 30
Shale, dark grey to black; a few sandstone bands.............- 154
Shale, dark grey, with many thin sandstone bands............- 257
Shale, dark grey to black, with a few thin sandstone bands..... 188
Shale, dark grey, with many thin sandstone bands............. 84

ROvaIGtICK ESS are tr etetatct mie sterevereiaretseerencaa storel anes 713

Another section of the uppermost part of the formation was measured
by. Wickenden and Shaw on the east side of the east branch of Bowlder
Creek; it may include beds of the overlying Dunvegan formation:

i Thickness
Top of Section weet
Sandstone, grey, with shale parting.........--..-+2+-+e++ee+s 22-3
Shale, dark grey, blocky, with thin sandstone beds...........-. 33-0

Conglomeratic sandstone, grey; pebbles } to 4 inch; a few small
ironstone concretionS............-+-c+eeeseereeee eteeees
Shale, dark grey, with many beds of sandstone; contains many

fragments of fossil plants..........-..-+.++200005 Spo0nop 10-2
Sandstone, coarse-grained, conglomeratic; pebbles § to + inch... 1:0
Shale, dark grey, with many thin sandstone beds.............- 5-0

Motalitnicknesss orice utter everta crn erealarete total