24

have numerous branches. Many of the larger branches of the diagonal veins
follow the direction of the transverse veins and appear to be transverse
veins joining stronger diagonals. Many branches are curving and have no
prevalent direction of strike. The types instead of crossing each other com-
monly join in a jumble of veins suggesting that the vein fractures were
formed by one stress and at the same time. :

The two types are alike in mineralization. They are quartz veins,
many of which have some tan-coloured ankerite, particularly along the
walls, and some of them contain some sericite. They contain as a rule
sulphide ranging up to 50 per cent by volume. The sulphide consists of
pyrite with some arsenopyrite and small amounts of sphalerite, galena,
galenobismutite, and cosalite.1 The sulphides are very coarse grained
and pyrite cubes one inch to the side are not uncommon. Free gold occurs
with the sulphide in grains of all sizes from nuggets down to minute
specks. Nugget gold amounts to an ounce in about 50 tons of ore. The
galenobismutite and cosalite occur sporadically in small bunches com-
monly associated with much coarse gold. The veins also contain small
quantities of scheelite and a minute quantity of a telluride. The quartz,
ankerite, pyrite, and arsenopyrite are early in the vein formation, but the
galenobismutite, cosalite, and gold associated with these minerals, and
also some galena commonly spread out from small nests into cracks tra-
versing the earlier vein matter. These minerals are, therefore, late in the
period of vein formation. Some of the gold is included in early sulphides
and appears to have been deposited early.

A noteworthy feature pertaining to the relation of the veins to the
country rock is well exemplified at the mine. The veins rarely cross
through divisions of dissimilar rock type. Many veins traverse only
part of one division. The explanation of this behaviour is presumably
that the different rock types reacted differently to the fracture forming
stresses. At one place one division yielded by fracturing more easily than
an adjoining division, and at another place the second division yielded
more easily than the first. In general, however, soft caleareous sedi-
ments and graphitic schists rarely fractured. The best fractures appear
to be in slightly fissile argillaceous quartzites.

Although the veins exposed by the 1,500 level occur throughout the
level, there are three groups of veins where the veins are bigger or more
closely spaced or more persistent. The two groups nearest the portal were
made by the joining of several fairly strong transverse and diagonal veins.
The third group is the Sanders vein zone, consisting of several parallel, per-
sistent, transverse veins. There appears to be another group of parallel
transverse veins on the Pinkerton and Goldfinch claims, but underground
development although it has cut one or more of the Pinkerton veins has
not been extensive enough to show that there is a group at depth.

Several transverse or diagonal veins and also a large strike vein are
exposed on the Cariboo No. 1 claim south of the present face (September
1934) of the 1,500 level. The strike vein called the Wells vein consists of
a number of closely spaced, 6-foot veins across a width of 20 to 50 feet.

1 Galenobismutite and cosalite have been identified by H. V. Warren.

“Mineral f i
Gold Quartz Mine”; The Miner, vol. 7, No. 7, pp. 287-288 (1934). reboey oF the! Cariboo