163

bulk of the rock is light green and not porphyritic. Narrow, dark, lampro-
phyre dykes are common in the vicinity of the mine, but are uncommon
in the mine workings.

Fractures or shear zones penetrating the porphyry and the large
inclusions of greenstone appear to be larger and more persistent where
they traverse porphyry than where they cut greenstone. The ore-bodies
occupied fractures, and fracture or shear zones, and most of the ore lay in
porphyry near the southwestern, southern, and southeastern contacts of
the body.
~The Premier ore-bodies are on the east side of Cascade creek between
the elevations of 700 feet and 2,100 feet. The main ore zone strikes south-
west but down hill swings from southwest to west to northwest. ‘The north-
easterly striking part of the zone is from 1,500 to 2,000 feet long in Premier
ground, the northwesterly striking part is about 3,000 feet long.

Most of the ore-bodies bottomed above the lowest adit level, No. 6,
at an elevation of 773 feet, but some ore has been stoped down to this
level and an unknown quantity has recently been discovered 150 feet below
No. 6 level. A large part of the northeasterly striking part of the zone
was a wide body of solid ore. The northwesterly striking part of the zone
was of much lower grade and only a few ore-bodies were found in it. The
ore-bodies were in general 30 feet or less in width, except at the bend where
a width of more than 50 feet was mined. Several parallel ore-bearing
veins a few inches to 6 feet wide were found 300 feet or less south of the
bend in the zone and of the northeasterly striking part of the zone.

The northeasterly striking part of the zone was mostly ore with several
higher grade bodies, from the surface downward to below No. 4 level (1,329
feet), but not as far as No. 5 level (1,076 feet). The upper part of the
zone dipped about 70 degrees northwest and the lower part about 45
degrees northwest. The ore shoots plunged steeply to the southwest. The
strike length of the ore-bearing part of the zone was greater on the second
and third levels than at the surface or at greater depth. Only a few short
ore shoots reached No. 5 level and only one as far as No. 6 level. The
newly discovered ore-body, 150 feet below No. 6 level, may be part of a
shoot not found in higher levels. At the bend the whole zone was an ore
shoot from some distance above No. 3 level down to No. 5 level where it
was considerably shorter than elsewhere. The ore shoot dipped about 80
degrees and plunged steeply to the west. The northwest zone dipped
steeply northeast and the few ore shoots plunged steeply northwest. These
ore shoots did not go far below No. 4 level (1,329 feet).

The ore was, for the most part, fairly solid sulphide consisting at depth
of pyrite, galena, and sphalerite with minor amounts of chalcopyrite.
From a short distance below No. 3 level to the surface the ore contained
important amounts of polybasite, ruby silver, argentite, native silver,
electrum, native gold, and tetrahedrite, some of which contained much
silver. Locally in the northeastern sector of the zone the ore consisted of
quartz containing disseminated ore minerals. At the ends of most ore
shoots ore gradually gave way to silicified country rock containing dissem-
inated pyrite and narrow streaks of ore minerals. The ore of the upper
part of the mine was probably finer grained than that in the lower part.