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The conglomerate of the Sifton formation is described by Roots (1948).
It consists ‘‘of subangular to rounded pebbles, averaging about 13 inches in
diameter, of limestone, sandstone, schist, slate, and quartz, in an impure
silty matrix. Water-worn, subangular pebbles and boulders up to 8 inches
in diameter of blue-grey or buff-coloured limestone, mostly well-bedded,
comprise about 70 per cent of the rock. About 15 per cent is composed of
pebbles of brownish grey to buff-coloured, medium- to fine-grained, well-
bedded, calcareous sandstone. Minor constituents include pebbles of
white quartz, blue-grey chert, or highly silicified limestone, and a bright
red, soft, sheared rock that may be a ferruginous limestone or slate or a
weathered volcanic rock. The matrix of the conglomerate is shaly to
silty, highly calcareous, and locally ferruginous.

“The conglomerate is roughly sorted, but only local evidences of
bedding could be obtained.... [It] outcrops on a long, low ridge that
trends parallel with the trench. No estimate of the thickness of the
conglomerate was obtained.”

Sifton Pass

The Sifton formation has been described by Hedley and Holland (1941).
It extends along the Rocky Mountain Trench for 10 or 15 miles north and
south of Sifton Pass, and “locally to elevations of about 5,000 feet, or
2,000 feet above the valley floor’.

Conglomerate is the most abundant sediment, but “local, minor beds
of sandstone and shale” are present. Fragmentary plant remains are
common in the sandy beds and coal seams are recorded. A non-marine
origin is inferred.

“The sands and shales, locally strongly carbonaceous, are for the most
part weakly coherent.

“The conglomerate is strongly cemented and is a hard, resistant rock,
but on weathering tends to break down so as to free the constituent peb-
bles.”” The size of the well-rounded pebbles is commonly ‘“‘between that of
a hazel-nut and anegg. The matrix is finely conglomeratic or sandy.
Constituent materials are all sedimentary, among which limestone is always
present and predominates locally; in some of the exposures, the proportion
of limestone is 8 to 1 and the matrix is calcareous. Other pebbles are
shales, sandstones, argillites, quartzites, and cherts; some black chert
pebbles, commonly rather small, are everywhere present. No igneous
pebbles are found, and none of schists or rocks metamorphosed beyond
the grade of phyllite’. Hedley and Holland do not discuss the source of
these sediments, but they note that the “beds are clearly unconformable
with the underlying rocks”. The relation of this formation to the Cassiar
batholith is not stated and is probably unknown.

Age and Correlation
(See Figure 12)

Plant fossils collected by McConnell suggested an Upper Laramie age
to Sir William Dawson. They were restudied by W. A. Bell of the Geo-
logical Survey, who proposed an Upper Cretaceous or Paleocene age.

Bell also examined a collection made by Hedley and Holland. He
states that “several fragments of dicotyledonous leaves are present, and

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