4

The boulder clay in this district has been reworked in part by the
rivers, and partly removed; some of it has been redeposited as finely
stratified muds and sands. Samples of these muds from the Bulkley River
valley near Smithers have been tested and a report upon them is given on
page 00-~ The plastic character of the boulder clay cut through and used
as filling material for the Grand Trunk Pacific railway is the cause of the
slides which have occurred along the line.

Glacial strie are found on the west side of Glen mountain in three
sets—one north 13 degrees east, one north 21 degrees east, and an older set
north 6 degrees east overridden by the other two. On Ninemile mountain,
at 5,000 feet altitude, towards the west side, the striz are north 31 degrees
east, and the movement was apparently north to south. All the above
bearings are with reference to true north. In most cases the hills were
covered with vegetation, or were weathered so that no striz were visible.

DRAINAGE.

Besides the two main rivers, the Bulkley and the Skeena, which
traverse this district, there are numerous smaller streams tributary to
them, which reach all parts of the area. All these streams, especially those
radiating from the Rocher Déboulé group, have very steep gradients and
would furnish considerable water-power (See Plate IIA). The Bulkley isa
turbulent river, flowing through a deep, narrow canyon for several miles

above Hazelton and is capable of furnishing all the power necessary for
’ the whole district. -

GENERAL GEOLOGY.

The bedded rocks of the Hazelton district are all of the Hazelton series,
described by Leach from the Telkwa district? and extending north into the
Groundhog, as noted by Malloch’. Extending across the southern part
of the Rocher Déboulé group of mountains, are interbedded flows and
coarse, ill-assorted tuffs or tuff-agglomerates (See Plate ITB). North of
the central portion of the group the series becomes more and more evenly-
bedded, with well-assorted material, distinctly banded, and with very
slight gradation from one band to the next, but all are tuffaceous in com-
position; this is well illustrated by Plate IITA.

The beds exposed in the canyon of Bulkley river contain an
abundance of plant fossils in some layers, and similar occurrences of fossils
are found northward to the limits of the sheet, but much more sparingly.
W. J. Wilson reported that these fossils seem to indicate the very top of
the Jurassic or perhaps the lowest Kootenay rocks. Near the northern
edge of the sheet, on Ninemile mountain, there is an horizon containing
an abundant marine fauna mostly of pelecypods. A determination by
Dr. T W. Stanton of the marine fossils collected, places the age of this
series as “most probably upper Jurassic.”

A folding of these rocks, which is well seen in the Bulkley canyon
above New Hazelton, took place with axes approximately northeast-south-
west (true). This folding was followed by the intrusion of small stocks
or batholiths which now form the cores of Ninemile, Fourmile, and Rocher

1Geot. Surv., Can., Sum. Rept., 1910, p. 91.
2 Geol. Surv., Can., Sum. Rept., 1912, p. 76.

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