100

the creek enters from the east (Figure 16). Ahbau lake is 6 miles long and
from its southern end a good pack-trail runs 18 miles south to Cottonwood
ranch, 20 miles from Quesnel on the Barkerville road. Guthrie and Gray
bonded the property to Oscar W. Alston and associates of New West-
minster, in the autumn of 1919.

The ore-bearing veins consist of galena (lead sulphide), zinc blende
(zine sulphide), and pyrite (iron sulphide) in a gangue that is almost entirely
quartz with films of sericite. The sulphides lie in masses and veinlets
withia the quartz, and where pyrite occurs with galena o” zinc blende it lies

in many cases on the outside of these masses, next to the quartz. Sericite, |

greenish white and micaceous, lies in cracks in the quartz. Pyrite is found
in the wall rock, apparently formed after the rock had been metamorphosed
to schist. The probable order of formation is, therefore, quartz, then pyrite,
and afterwards galena, zinc blende, and sericite. The country rocks con-
sist of blue-grey quartzite of very fine grain, and phyllite or argillite of
which certain beds are carbonaceous. The argillites and quartzites are
nearly of the same composition, that is, they consist mostly of quartz with
minor amounts of muscovite mica, but the argillites are of finer grain than
the quartzites. Both types of rocks are foliated or schistose, that is, they
split: easily along closely spaced parting planes. Two dykes occur close to
the main quartz vein, intruding the country rocks. One is an aplite, the
other a feldspathic porphyry, probably andesite,

Ore has been.found in two places (Figure 16). On the north side of
the creek, about 300 feet above its bed, a quartz vein carrying galena and
pyrite crops out in a cliff on the side hill. This vein is from 33 to 4% feet
wide, strikes north 78 degrees east and dips 50 degrees to the west. At the
time of visit it had been proved over a horizontal distance of about 150
and a vertical distance of 80 feet; since then it is said to have been encoun-
tered in a tunnel below, increasing the proved dimensions both horizontally
and vertically. Two nearly parallel quartz veins lie 25 and 100 feet north

. and up the hill from the main vein. They are 13 and 2 feet wide, respec-

tively. Other small stringers were seen, one of which lies close to and
south of the main vein and trends away from it at a low angle. About
1,000 feet to the southwest in the creek bottom are lenses of quartz and
galena 15 to 20 feet apart, that lie along the planes of schistosity of the rock.
The largest is 4 feet at its widest point; it is exposed for about 13 feet on
one side of the creek and may continue across the stream. It strikes south
50 degrees east and dips 45 degrees to the northeast. A series of parallel
lenses occurs, apparently, in this place, for galena float has been found 60
feet to the east up the creek, but here, and on top of the hill, the drift
cover is an impediment to prospecting. The general strike of the planes
of schistosity in the rocks and of such true bedding planes as were observed
is to the northwest, with dips of from 24 degrees to 55 degrees to the north-
east (Figure 16). At the upper quartz occurrence there is 4 cross anticlinal
fold with a northeast trending axis. The series of nearly parallel ore-
bearing quartz veins cross the crest of this fold at an angle.

Two short tunnels had been run near the main quartz vein in July,
1919, the longest following the vein for 15 feet. Twovopen-cuts had been
made on the lenses of quartz in the creek bottom and about 40 cubic yards
of rock had been moved. The writer sampled across 4 feet of the ore-body

sail