represents the base of the Dome Creek Formation, eroded
away in other parts of the area in pre-Black Stuart Group
time. Mansy (1970) also mapped this horizon as Dome
Creek Formation.

Age and correlation. Lang (1938, 1947), Sutherland
Brown (1963) and Mansy (1970) described Lower Cam-
brian trilobite collections taken from the shales overlying
the Mural Formation on Kimball Ridge. Mansy reinter-
preted the collections of Lang (1938, 1947) and Suther-
land Brown (1963) as being from the Dome Creek
Formation.

Lang (1938, 1947) found the following fossils which
were identified by C.E. Ressor who assigned them an
Early Cambrian age, except for the new genus related to
Kootenia which may be Middle Cambrian;

Paedeumias sp.

Kootenia sp.

Salterella sp.

Bonnia sp.

New genus related to Kootenia
New genus of Ollenellid Trilobite

Sutherland Brown (1963) reported:

Bonnia sp.
from the northwestern locality and:

Ogygopsis klotzi Rominger
from the southeastern locality. Determinations were made
by V.J. Okulitch who assigned the Bonnia sp. to the
upper Lower Cambrian and the O. K/otzi Rominger to
the Middle Cambrian.

Mansy (1970) collected:
Ogygopsis sp.
Bonnia sp.
from the northwestern locality and:
Ogygopsis sp.
from the southeastern locality. Determinations were made
by W.H. Fritz who assigned them a late Early Cambrian
age.

Northwest of Kimball Ridge, in the canyon of the
Cariboo River, an area not mapped for this report,
Sutherland Brown (1963, p. 28-29) recovered fossils from
a ‘“‘black fetid limestone’’. They were identified by
V.J. Okulitch as:

Obolus sp.

Glossopleura cf. Stenorhacis Rasetti

Paedeumias (Olenellus) gilberti
The brachiopod Obolus is Middle to Late Cambrian.
Glossopleura cf. Stenorhacis Rasetti is Middle Cambrian
and Paedeumias (Olenellus) gilberti is Early Cambrian.
This faunal assemblage is probably from Dome Creek
Formation. Campbell et al. (1973) reported upper Lower
Cambrian and Upper Cambrian fossils from the type sec-
tion in Cariboo Mountains and only one possible occur-
rence of a Middle Cambrian Ogygopsis sp. They con-
cluded that the Middle Cambrian may be represented by
a lacuna (see Campbell et al., 1973, p. 12). Considering
the presence of two Middle Cambrian trilobite indentifi-
cations from the local area such a lacuna may not extend
westward beyond the Cariboo Mountains.

22

Campbell et al. (1973, p. 56) suggested the Dome
Creek Formation is a basinward restricted marine facies
synchronous with the eastern Cambrian shelf facies of
the Rocky Mountains. Similar basinal facies transitions
occur in the Upper Cambrian of northern British Colum-
bia where the shale facies of Kechika Formation corre-
late with those of the Dome Creek Formation (see Cecile
and Norford, 1979, and Gabrielse, 1975, for discussions
of Kechika Formation and correlative rocks in northern
British Columbia).

Black Stuart Group

The Black Stuart Formation as originally mapped by
Mansy (1970) is here elevated to group status because
it contains distinct units, three or more of which are
separated by unconformities and because it spans the
Ordovician to Mississippian. The Devono-Mississippian
Waverly, Guyet and Greenberry formations are placed
in the Black Stuart Group because they intertongue with
it and/or are the same age.

The Black Stuart Group is divided into three infor-
mal units (following Mansy, 1970, and Campbell et al.,
1973: chert-carbonate; black pelite, which both under-
lies and overlies the chert-carbonate unit; and sandstone,
which overlies the other two units) and into three
formations.

The dolostone and chert breccia of the chert-
carbonate unit are unique to the Black Stuart Group. The
black phyllite and argillite is generally more siliceous than
other pelites of the Cariboo Terrane but similar varieties
occur in the Barkerville Terrane. The association of the
Black Stuart Group with volcanic rocks of the Waverly
Formation and conglomerate of the Guyet Formation
distinguishes it from older units.

The Black Stuart Group primarily underlies the area
southeast of Antler Creek, being best exposed and most
diverse near Black Stuart Mountain. Black pelite of the
group continues northwest in a thin belt to Big Valley
Creek. The Black Stuart Group was first named and
described by Mansy (1970) as a formation in the Black
Stuart Mountain area. Campbell et al. (1973) recognized
equivalent strata to the north of Cariboo River and
mapped them as far north as Antler Creek. The only
other locality where Black Stuart Group is known is at
Haggen Ridge northeast of the map area. Mansy and
Campbell (1970) reported a thickness of approximately
850 m in the type area. Though Campbell et al. (1973)
did not report any total thickness they considered the
group to be less than 850 m.

South of Cariboo River, the Black Stuart Group is
probably less than S00 m thick. In the Cunningham Creek
area, southeast of Mount Tinsdale, the group may be
thicker, but this may be due to structural complications.

Chert-carbonate unit

The chert-carbonate unit consists of various types of
dolostone, dolostone breccia and conglomerate and chert