18

three sides by steep slopes rising to over 5,000 feet. A little surface
prospecting was done here in 1923 and 1924, but no large deposits were
found and the claims were soon dropped.

The floor of the Silver Basin valley is comprised of a succession of
volcanics of which andesite, dacite, and tuff are predominant. They strike
south 70 degrees east and dip 60 degrees south. Several, small, quartz-
albite dykes and lamprophyre dykes were seen along the creek at eleva-
tion 4,100 feet. On the steep slope north of the valley floor the eastern
end of a large diorite stock outcrops between elevations 4,500 and 5,000
feet and is cut by similar dykes.

A short distance below a 50-foot waterfall, at elevation 4,150 feet, a
quartz vein averaging 12 inches in width outcrops for about 200 feet along
the south bank of Chimdemash creek. The vein strikes north 60 degrees
west and dips 45 degrees south. At its west end the vein gradually narrows
and is then drift covered. A 10-foot adit was driven across the east end of
the vein along a cross fault that strikes north 65 degrees east and dips
50. degrees southeast. At the point of faulting the vein is 3 feet wide, but
it narrows to 1 foot only 15 feet west. The vein quartz carries a sparse
dissemination of pyrite and tetrahedrite, with which a little calcite is asso-
ciated. Similar vein matter 3 inches wide occurs along the cross fault. A
3-foot channel sample taken across the vein at the adit assayed: gold,
none; silver, 1-58 ounces a ton.

About 1,700 feet farther east, at elevation 4,450 feet, a 12-inch vein
of quartz and calcite in the stream bed of Chimdemash creek occupies a
fault fracture for a length of about 100 feet. The fault strikes north 60
degrees east and dips 70 degrees northwest. It strikes at a small angle
diagonally across the stream and its continuation a few feet beyond the
vein is drift covered in both directions. The vein contains narrow seams
of tetrahedrite and bornite. A 13-inch channel sample taken across the
vein at the water’s edge assayed: gold, none; silver, 9-70 ounces a ton;
copper, 1-0 per cent. At a cut on the vein a representative sample from
a pile of hand-sorted ore assayed: gold, 0-02 ounce a ton; silver, 71-88
ounces a ton; copper, 6:62 per cent.

Silver Crown Group (11)

References: Ann, Repts., Minister of Mines, B.C.: 1923, p. 103; 1924, p. 90. Geol.
Surv., Canada, Sum. Rept. 1925, pt. A, p. 113.

The Silver Crown claims, staked by J. D. Wells in 1923, are on the
summit of the mountain immediately east of the head of Chimdemash
creek, about 14 miles east of Usk. A foot trail from the Chimdemash
Creek trail leads up to the claims through a pass at the east or upper end
of the Silver Basin valley. Several small cuts were made on narrow, silver-
copper veins.

The rocks in the vicinity of the Silver Crown claim post, at elevation
4,900 feet, comprise a series of grey and purple andesite flows, which strike
southeast and dip steeply. An altered dyke of light-coloured quartz diorite
outcrops 70 feet west of the claim post. The dyke is about 25 fect thick,
strikes northeast, and dips 40 degrees northwest. Two parallel quartz veins
occur on the east side of the dyke and strike at right angles to it. One of