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limestone. They carry the Beyrichites-Gymnotoceras fauna (McLearn,
1948), which identifies the upper part of the Toad formation. The lower
part of the Toad is concealed below the level of McTaggart Creek.

It is inferred that the Toad formation also outcrops on Mount Withrow,
west of Mount Hage, and on the north side of Sikanni Chief Valley, for
specimens of the Beyrichites-Gymnotoceras fauna, typical of the upper part
of the Toad formation, were collected there by Hage (1944). No descrip-
tion of the lithology has been given.

Muskwa River Basin

The Toad formation is known to underlie a large area in the basin of
Muskwa River. No details of lithology or occurrence have yet been
published, but many collections of the Beyrichites-Gymnotoceras fauna
forwarded to the Geological Survey for identification bear witness to its
presence in this part of northeastern British Columbia.

Tetsa River Valley

The Toad formation outcrops in Tetsa Valley, where the upper part
is well exposed in low cliffs or ledges along the Alaska Highway from mile
374 to about mile 378, and in ledges on the southern slopes of Cameron,
Smith, and Shaw Hills (See Figure 7). The Triassic beds outcrop on the
axes of the anticlines, and the overlying dark shales of Jurassic or Cretaceous
age outcrop in the synclines. The lower beds of the formation are con-
cealed below river level and so do not outcrop in this part of the valley.

First observed by Williams (1944), this section was later studied by
McLearn (1946, 1948). The exposed beds consist of about 500 feet of
dark grey, partly carbonaceous, thin-bedded, calcareous shales, shaly
calcareous siltstones, and thin lenticular beds of dark limestone. Near
the top the beds become coarser and more massive, and, at the top of the
section, some thick-bedded, grey, calcareous, fine sandstones and grey
limestones, with a few brachiopods, may belong to the basal part of the
Liard formation or may be considered beds transitional into that formation.

Marine fossils are common in the lower part of the 500-foot section
outcropping in this part of Tetsa River Valley, and have been collected
along the highway on the axes of the Smith and Shaw anticlines and east
of the axis of the Cameron anticline and on the south slope of Cameron
Hill (See Figure 7). They are all of the Beyrichites-Gymnotoceras fauna,
and include species of the ammonoid genera Parapopanoceras, Longo-
bardites, Beyrichites, and Gymnotoceras (McLearn, 1946, 1948).

The Toad formation may also be exposed in a low ledge, beside the
Highway near mile 383, where dark calcareous siltstones contain poorly
preserved shells, possibly of the Beyrichites-Gymnotoceras fauna.

Liard River Valley

At the type locality on Liard River (See Figure 4) at and near the
mouth of Toad River, the Toad formation consists of about 800 feet of
“brown and black, platy shales, and grey to brown and yellowish, thin-
bedded siltstone, with a few thin, lenticular beds of grey to black, fossili-
ferous limestone. These strata are particularly well exposed in steep,