293

The beds ‘are crushed, folded, and faulted.::On the west they lie, close.
to the, eastern side of a pronounced anticline. in adjoining Middle
Triassic. strata. The variability of strike and dip of the two groups.
suggests @ faulted contact at the front of the anticline, which is.
closely folded and faulted on its western limb. The absence of Upper .
Triassic and Jurassic strata would also lend support to the occurrence
of such a fault were it not possible that beds of ee ogee may never
have been deposited in this region.

Farther east, near mile of laliipins ees a
road-cut. peracetic

One poorly preserved Cardium sp. was found near mile 86 in
dark grey sandstone. Lignitic beds measure as much os 4 feet in -
thickness, but no true coal was found. The proximity:.of those beds ‘60. ack

the Middle Triassic rocks on the west suggests a low position for them a eae

in the Cretaceous section, Their relationships on the east ore unknown,
but they appear to assume the regular regional dip toward the east, and .
the broad: valley of Mill -Croek is: suggestive of erosion of soft beds
such ®8' shales of thé Fort St. John group... The assumed oge is lower
Lower’ Creteccous, or about the Cau RTE Lone. of the ue group of the
Peace: River ‘ares . :
re ha ee ; yd

Fort St. soon: The wide plains area extending 57 aeiive
westward fron Fort Nelson is underlain by. Soft, sandy, dark brown or
black shale. Because of its softness it is open exposed ng the

Highwoy.

At mile 8 (R. Melville Smith Gorctruction Camp) a. small stream: .
flows: southward from a hill that rises 200 to 300 feet above the plain.
The hill consists of black, sandy shale, with small concretions in some’:
of the beds. =A bore-hole, drilled for’ water, had penetrated to a depth
of 208 feet in this shale. ~The formation-heré™ ‘“is*nearly horizontal. “At
mile 27, black’ shale occurs in a road-cut, and souen Oe mile 39 a large
cnet g outcrop occurs: in Rledo Ravers:

West of mile 50 the Highway yaies the Foothills, there con~
sisting of horizontal dark ‘shale. About 200 feet of shale is: exposed
between mile 50-and mile 51 where it is overlain by sandstone. The shale -
is nodular, commonly rusty weathering, with sheared vertical surfaces, .

striking south 50 degrees west. At the forks of Tetsa ond Muskwo: Rivers, ©;

south of mile 52, exposures of dark shale show in the banks. Along the
old road, south of mile 54, a 500-foot section is in part exposed. This
consists of several ledges of thin-bedded, grey-blue sandstone weathering
buff, with covered intervals above and below strongly suggestive.of shale
interbeds. At the top of the section sandstone occurs interbedded with. .
shale. Worm burrows are numerous on some slabs, and again near mile 53:
and mile 54 on the new location of the road Posidonomya nahwisi var.
moberliensis and P. nahwisi var. goodrichensis were found. Just below

these fossiliferous béds poorly preserved plant remains and & 3-inch

coal seam occur in the sandstone. McLearn correlates this part of the
section with the Goodrich formation of Pine River Valley... At-Commotion
Creek this is classified-as the second highest member of the Fort St.
John group. Along the Highway south of Fort Nelson the shale is ap- =
perently continuous with the Buckinghorse formation os the same group
(Hage, 1944).

To the west, the sandstone beds dip downward to a syncline,
beyond which they rise gently into Teepee Mountain. This somewhat
round-topped hill is situated between miles 60 and 61 on the new'road
and mile 61 on the old location. The strike of the strata varies from
north to northwest, the dip being easterly at from 55 to 10 degrees.
Pepper and salt sandstone outcrops along the road on the south side of
the mountain, soft sandstone and shale beds continuing upward. About.