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on the McPherson level 1,240 feet northeast of the portal. Their line of
junction between this level and the surface plunges 75 degrees to the
southwest.

At an elevation of 3,575 feet northeast of the No. 1 fault, and just
below the Compressor level, the Henderson vein-lode is joined by the Fault
Plane vein-lode. The line of junction of these two lodes plunges at a low
angle to the southwest. The stronger, Henderson vein-lode has a vertical
dip below the junction, whereas the Fault Plane vein-lode strikes roughly
parallel to the Henderson but dips at 55 to 60 degrees to the southeast.

A fourth vein-lode, the Dome, lies 1,350 feet southeast of the
Henderson.

The Henderson vein-lode has been drifted on for 250 feet on the
Thompson level, 1,450 feet on the 65 level, 500 feet on the 145 level,
950 feet on the Compressor level, 425 feet on both the 300 and 400 levels,
1,250 feet on the Mill level, and about 900 feet on the 600 level. An
extensive system of stopes extends from the 500 level through to the surface,
and there are two small stopes on this vein-lode on the 600 level (See
Figure 10). The commercial silver-lead-zinc vein deposits were found
over a length of 1,050 feet at the surface and for 750 feet along the
500 level. The eastern boundary of the ore follows a line that plunges
70 degrees southwest from the upper end of the open stope above the
Thompson level. The western boundary of the stoped areas follows a
line plunging 77 degrees northeast, so that in longitudinal section (See
Figure 10) this composite zone of ore shoots is seen to narrow at depth.
Judging from mine assay plans, the ore mined ranged from 6 inches to
4 feet in width and assays exceeding 100 ounces of silver a ton were not
uncommon over widths of 12 to 15 inches. A series of fifty-three samples
taken at 5- or 6-foot intervals along the roof of stope 500A, 90 feet above
the 500 level, over a length of 280 feet (March 1929), ranged from 7 to
48 inches in width and assayed from 4-6 to 1,120-4 ounces of silver a ton.
The average width of the fifty-three samples was 20 inches, and the average
grade was 106 ounces of silver a ton. A series of eighteen samples taken
close to the present roof of stope 500C (September 1929), over a length
of 100 feet, gave an average assay of 51-3 ounces of silver a ton across
an average width of 9 inches. Below the 500 level the vein-lode is narrower
and values are lower. According to mine assay plans, a series of fifteen
samples from stope 600A, taken 30 feet above the floor of the 600 level
(December 1929), ranged from 4 to 10 inches in width and assayed from
4-2 to 230-6 ounces of silver a ton. The average width of the fifteen
samples was 6-2 inches and the average grade 76-2 ounces of silver a ton.
The plans show that the vein-lode in 600C stope also averaged about
6 inches in width, but that the veins assayed under 20 ounces of silver
a ton.

Near the portal of the McPherson adit the Henderson vein-lode
includes seven parallel fissures spaced across a width of 4 feet. The
rhyolite wall-rock is much cross fractured between these fissures, and in
one zone is brecciated across a width of from 2 to 12 inches. The brecciated.
rock fragments in this zone are cemented by vein quartz, sphalerite,
arsenopyrite, galena, tetrahedrite, pyrite, and chalcopyrite. Sulphide veins
composed of similar minerals occur along the other fissures. These veins