19

Cache Creek series, Kamloops map-area Slide Mountain series, Barkerville map-
area
Marble Canyon limestone with some minor intercalations Limestone—grey to white, finely crys-
of volcanic rocks, argillites and cherty quartzite, at talline, thickly bedded series with
least 3,000 feet thick some chert (exposed along Bear
ee Swamp river, Spectacle lake,
etc.

Voleanic materials and limestones with some argillites, (Thinly interbedded, grey and green
cherty quartzites, at least 2,000 feet thick cherts and argillites of the Antler
formation 3,500 + feet thick.

Cherty quartzite, argillites, volcanic materials, and ser- )Basic volcanic rocks of the Waverly
pentines with some limestone (crinoidal), at least 4,500 formation 2,000 + feet thick. Green-

feet thick ~ berry limestone (crinoidal) 400 feet
thick

Base unobserved Guyet basal conglomerate 900 feet
thick

Richardson’s discovery of Fusulina in the Marble Canyon limestone
in 1871? fixed the age of the upper part of the Cache Creek series as Carbon-
iferous and probably Pennsylvanian, whereas the determination of the
Mississippian age of the Greenberry limestone, lying at the base of the
cherts and argillites which are so typical of the lower part of the Cache
Creek series, rather definitely fixes the entire Cache Creek series as Missis-
sippian to Pennsylvanian.

Guyet Formation

Distribution. This formation consists of the conglomerate at the base
of the Slide Mountain series, and constitutes one of the chief evidences of
the unconformable relations of the series with the underlying rocks. It
occurs in a narrow belt trending northwest from the type occurrence on
mount Guyet along the southwestern slopes of mount Howley, Waverly
mountain, mount Greenberry, and mount Murray to Two Sisters mountain
beyond the northern border of the map-area. The best exposures of the
formation are: along the Bear Lake road, just northeast of the crossing
over Eightmile creek, where a splendid section of almost the entire form-
ation is exposed; on the western slope of mount Greenberry; and on the
top of mount Guyet.

Lithology. The formation grades in character from a somewhat
decomposed schistose conglomerate at the base, where no sharply defined
boundary with the underlying rocks is observed, to a massive, heavily
bedded bouldery deposit towards the middle part, and a coarse-grained,
gritty quartzite near the top. In the uppermost part the pebbles and rock
fragments lie in a matrix of grey limestone. A considerable variation in
thickness occurs from place to place, but an insufficiency of continuous
exposures prohibits a statement of the extent of the variation.

A careful examination of the conglomerate near the mouth of Eight-
mile creek revealed the presence of pebbles, fragments, and boulders of
the following rock types:

Grey quartzite, similar to part of the Richfield formation

White quartzite, similar to part of the Richfield formation
Dark grey limestone

1Geol. Sury., Canada, Ann. Rept., vol. VII, pt. B, p. 46 (1895).
2Geol. Surv., Canada, Rept. of Prog. 1877-78, pt. B, p. 88. Quart. Jour., Geol. Soc., vol. 35, p. 69.