40

400-foot rock bluffs on the north side of Liard River between 1 mile and
2 miles downstream from the mouth of the Toad, where the Liard cuts
easterly across the formation’ (Kindle, 1948). They rest conformably on
beds of the underlying Grayling formation, and are overlain disconform-
ably by the basal Jurassic or Lower Cretaceous shales of the Garbutt
formation. A 6-inch bed of limestone in this type section of the Toad
formation, 400 feet above its base and exposed “‘on the north bank of the
Liard, about 2 miles below the mouth of the Toad”’, is highly fossiliferous,
and carries specimens of the Wasatchites fauna. The same fauna occurs
in a thin limestone band on the northeast bank of Toad River, 2 miles
above the mouth of the Toad. “....1,000 feet downstream from the
6-inch Wasatchites bed [referred to] above, on the south bank of the Liard
and 300 feet higher in the section, or 80 feet below the top of the formation,
are several narrow beds of black limestone associated with dark, argil-
laceous shales. Both limestone and shale contain abundant fossils within
a [20-foot zone]...and concretions found in the shales are also fossili-
ferous” (Kindle, 1948). These fossils include species of the Beyrichites-
Gymnotoceras fauna, although Beyrichites and Gymnotoceras are not among
the genera represented.

Farther up Liard River, 8 miles southwest of the mouth of the Toad>
the formation is 1,800 feet thick, much thicker than at the mouth. Here,
on the north bank of the river are thin-bedded shales, sandstones, and
siltstones. ‘The shales range from brown to black, and are interbedded
with narrow grey and brown sandstone and siltstone beds. Towards the
upper part of the formation the sandstone beds are calcareous and contain
a few fossils. A 40-foot band of black, sandy limestone that occurs 150
feet below massive calcareous sandstones of the overlying formation
(Liard) is highly fossiliferous. It is underlain by 35 feet of black, platy
[fossiliferous}] shale”? (Kindle, 1948). From the limestone band, Kindle
collected the Beyrichites-Gymnotoceras fauna.

Age and Correlation
(See Figure 5)

The Toad formation represents a fairly long range of geological time,
as it contains a Lower Triassic fauna, the Wasatchites, near the middle of
the formation and a Middle Triassic fauna, the Beyrichites-Gymnotoceras,
near the top.

The Wasatchites fauna has not been found elsewhere in Canada and is
not known in Alaska.

In the Fort Douglas area, Utah, the Lower Triassic comprises the
Woodsideand Pinecrestformations. Itwasinthe Pinecrest, between the zones
of Meekoceras and Tirolites of Upper Owenitan age, that A. A. L. Mathews
(1929) recognized and described the ammonoid genus Wasatchites. With
it he recorded species of Xenoceltites, Hemiprionites, Gurleyites, Anasi-
birites, and other genera. With this Wasatchites fauna of Utah, the Wasa-
chites fauna of Liard River shows considerable resemblance: Wasatchites
canadensis is close to the coarsely ribbed Wasatchites perrini Mathews and
W. magnus Mathews; a Liard River specimen is close to W. meeki Mathews;
and some Liard River specimens resemble Xenoceltites hannai Mathews
(McLearn, 1945A).