24

steep eastern wall of the cirque. The vein occupies a fault along the north
wall of a quartz porphyry dyke about 15 feet wide. The dyke cuts a
coarsely crystalline diorite boss that intrudes the country rock of andesites
and volcanic breccia. In hand specimens the quartz porphyry dyke re-
sembles the white quartz-albite dykes described in other parts of the area,
but in thin section the rock was found to consist entirely of quartz, sericite,
and calcite, the secondary minerals evidently having formed through com-
plete alteration of the albite. Alteration of the adjoining diorite over a
width of 10 feet on each side of the dyke indicates a marked circulation of
heated waters along the walls of the dyke.

Along the bench the vein strikes south 60 degrees east and dips steeply
south. It ranges from 2 to 10 feet in width and contains a sparse dis-
semination of pyrite, chalcopyrite, and galena throughout, with several
short, rich ore shoots. Fifty feet from the edge of the glacier there is an
ore shoot in the vein approximately 1 foot wide and 25 feet long, comprised
of about 80 per cent of sulphide, chiefly galena, sphalerite, and tetrahedrite,
cut by narrow chalcopyrite veinlets. A channel sample taken across this
ore shoot by the writer assayed: gold, 0-16 ounce a ton; silver, 92-00 ounces
a ton; zinc, 17-28 per cent; lead, 6-10 per cent; copper, 1-42 per cent.
Forty feet farther west at a small test pit a 36-inch channel sample taken
across a sparsely mineralized part of the vein assayed: gold, a trace; silver,
1-80 ounces a ton.

The vein was seen to outcrop along its strike about 1,000 feet farther
west, near the base of a steep rock face that juts out into the glacier.
Honeycombed, steeply sloping ice prevented an examination of the vein at
this point, but it was seen from a distance to range from 2 to 3 feet in width
and to dip steeply to the south. Farther west its continuation is covered by
glacial ice.

As the vein is mostly concealed by steep, ice-covered slopes, develop-
ment would necessitate the driving of a long crosscut adit.

United St. Croix Group (16)
(See Figure 3)
Reference: Ann. Rept., Minister of Mines, B.C., 1914, p. 136.

The United St. Croix claims are on the summit of the mountain that
forms the divide between the headwaters of the north fork of Chimdemash
creek, the south fork of Legate creek, and St. Croix creek. The claims are
12 miles east of Usk and are reached by a branch pack-horse trail from the
Chimdemash Creek trail. The trail leads along the north side of the north
fork of Chimdemash creek to a grassy basin at elevation 3,100 feet. From
here a switchback trail leads up the steep slope to the summit (elevation
5,100 feet).

Many varieties of volcanic flows comprise the bedrock of the moun-
tain. The flows range from reddish to green and grey. Some are fine
grained, others coarse grained, amygdaloidal, and porphyritic. The
voleanics are cut by numerous granite and quartz-albite dykes.

At an elevation of 4,950 feet on the north fork slope a trench is cut
across a 12-foot zone of voleanic breccia that is impregnated with narrow