50

Sikanni Chief River Valley

A section of the ‘Grey beds’, but with long concealed intervals, can
be studied on the west slope of Mount Hage (See Figure 6 and Plate IV A).
The lowest strata are exposed on the east slope of Hage Creek Valley, where
they overlie the ‘Dark siltstones’ and comprise 50 feet of hard, massive,
thick-bedded, grey, calcareous, fine sandstone with species of the Nathorstites
fauna. These are overlain, on the higher eastern slope of this creek valley,
by massive, calcareous, fine sandstone with a 10-foot bed of grey limestone
at the top. Above this, across a nearly flat area, a concealed interval
extends to where ledges of massive, calcareous, fine sandstone with
pelecypods are exposed. From these ledges, up the steep slope of the
mountain, the beds, amounting to hundreds of feet in thickness, are con-
cealed. Above are ledges of massive, grey, fine sandstone and fine-grained
limestone. Near the top of the slope these beds are overlain by the darker
and finer grained strata of the Pardonet beds (McLearn, 1946A).

Not far from where Hage Creek issues on the flat bordering the main
river, are exposures of fine, calcareous sandstones and shaly siltstones
carrying species of the Nathorstites fauna. They evidently belong to the
lower part of the ‘Grey beds’.

Hage (1944) obtained fossils from the lower part of the ‘Grey beds’ on
Mount Withrow, but did not describe the section.

On the crest of the anticline crossing Sikanni Chief River east of the
mouth of Chicken Creek, the Pardonet beds are underlain by grey limestone
with Gryphaea and other fossils. It is probable that this limestone lies at
the top of the ‘Grey beds’.

Prophet River Drainage Basin

‘Grey beds’ with the Nathorstites fauna have been observed along
Prophet River. No particulars of lithology or succession are available.

Age and Correlation
(See Figure 5)

In the upper part of the ‘Grey beds’, a massive, mostly barren sandstone
occurs in the sections on both Brown and Pardonet Hills, just below the
Lima? poyana zone. It is doubtful, however, if this lithological correlation
can be carried very far.

The relation of the ‘Flagstones’, ‘Dark siltstones’, and lower part of
the ‘Grey beds’ to the Liard formation is a problem of local correlation.
The Nathorstites fauna ranges throughout the Liard formation. It is also
present in the lower part of the ‘Grey beds’ and in the ‘Dark siltstones’.
The ‘Flagstones’ are mostly unfossiliferous; however, in the section on
Fourth Gully, Mount Wright, the massive beds at the top of the ‘Flagstones’
carry brachiopods similar to, if not identical with, brachiopods in the
Nathorstites fauna and in the ‘Dark siltstones’ and lower part of the ‘Grey
beds’. If this means that the ‘Flagstones’ do carry representatives of the
Nathorstites fauna, then the ‘Flagstones’, ‘Dark siltstones’, and lower part
of the ‘Grey beds’ of the section on Halfway and Sikanni Chief Rivers are
to be correlated with the Liard formation on Liard River on the basis of
their common fauna.