agglomerate may represent direct volcanic activity trans-
porting material as flows (Sutherland Brown, 1957, p. 36)
and/or airfall debris or sedimentary transport of volcanic
material into a carbonate-rich basin. The carbonate
matrix is thought to be sedimentary and existed prior to
the accumulation of the basalt because of the breccia frag-
ments of laminated calcite found in the basalt of the
Loskey Creek exposure. The occurrence of calcite
throughout much of the Waverly Formation basalt may
indicate that it was derived from the volcanic material.
Ultimately both sources for the carbonate may be from
the basaltic magma. The sedimentary carbonate could
have formed by precipitation from circulating water fed
by a carbonate-rich magma.

Age and correlation. The Waverly Formation directly
overlies micritic limestone of the Black Stuart Group and
therefore is equal to or younger than the age of the lime-
stone; Middle to lower Late Devonian. It corresponds in
lithology and age to Devonian basalt of the Earn Group
from the Selwyn Basin (Gordey et al., 1982).

Guyet Formation

The Guyet Formation was introduced by Johnston and
Uglow (1926) as consisting of conglomerate, sandstone
and slate. Sutherland Brown (1957) redefined the forma-
tion, adding the Greenberry Limestone Member and
basalt. Johnston and Uglow designated the limestone as
an overlying formation and included the basalts in the
Waverly Formation. Sutherland Brown (1957) placed the
Guyet Formation with the Antler Formation in the Slide

28

Figure 18. Calcareous basalt agglomerate of the Waverly
Formation.
A) Basalt blocks in calcite matrix near Greenberry Mountain. (GSC
191014)
B) Basalt fragments in calcareous matrix on North Cunningham
Mountain. (GSC 191015)

Mountain Group. It is proposed that the Guyet Forma-
tion be further redefined. Firstly, it should be removed
from the Slide Mountain Group because it has no affini-
ties with the Antler Formation. The Guyet Formation is
interdigitated with the Black Stuart Group and is in tec-
tonic contact with the Antler Formation. Secondly, the
Greenberry limestone is reinstated as a formation. Lastly,
the basalt of the Guyet Formation is included with
agglomerates and volcaniclastics and those rocks are
named the Waverly Formation after Waverly Mountain
where they are well developed.

The Guyet Formation consists of quartzose sandy
conglomerate to breccia, muddy conglomerate to brec-
cia, sandstone and greywacke (Table 9 and 10). The con-
glomerate with its chert, pelite and local volcanic clasts
is distinct from other conglomerate of the Cariboo
Terrane. Its clasts and their inclusion in quartz sand or
black pelite matrix are distinguishing features. A similar
conglomerate occurs in the Hardscrabble Mountain suc-
cession of the Barkerville Terrane. Sandstone and blue
quartz clasts are found in the Hardscrabble Mountain,
but not Guyet Formation conglomerate.

The Guyet Formation is discontinuous throughout the
map area being exposed mainly in two localities, Summit
Creek-Alex Allan Creek area and from Mount Guyet to
the south slopes of Mount Tinsdale. It can be traced from
the Big Valley Creek area to south of Cariboo River where
it feathers out into black slates of the Black Stuart Group.
The conglomerate is found on the islands at the north
end of Swan Lake.