9

A crosscut tunnel has been run into the mountain for more than3,100 feet
at the 1,200-foot level and intersects four veins, giving a back of 180 feet
for the lowest vein, 460 feet for the next higher, 1,050 feet for the tramway
vein, and 980 feet up to the 500-foot level of No. 4 or the main vein. The
work at present consists of drifting on the lowest level of No. 4 and of
raising from it to the 500-foot level, with intermediate drifts to explore
the vein between the levels; at the same time development is being pushed
on No. 2 vein and good ore is being encountered, including a shoot which
is more than 70 feet long and averages 2 feet in width running 7 per cent
copper.

The Rocher De Boule property is located on Rocher Déboulé mountain
(Map. 1732) on the west side of Juniper creek 14 miles from its head, and
extends from the creek at 3,900 feet elevation, to the top of the ridge at
5,700 feet elevation. A series of approximately parallel fissures traverse
the hillside with a general strike north 80 degrees east (magnetic) and
with dips averaging about 60 degrees northwest. These fissures have
been formed by shearing, and the crushed country rock has been partly
replaced by mineralizing solutions, so that the fissures have become veins
containing valuable deposits of ore.

The veins are not of equal economic importance, nor are all parts of
the same vein equally valuable (Figure 1); and, although all the veins are
mineralized, only two of the five have been shown to contain high grade
ore-shoots in addition to the second grade or milling ore which is found in
ereater or less amount in all the veins. In the upper part of the highest
vein, for instance (Figure 2), there were four large bodies of high grade
copper ore of irregular shapes at approximately the same elevation, but
separated horizontally by 50 to 200 feet of vein material carrying much
lower values, and, in places, no values at all.

Factors Influencing Location of Ore-shoots. From the data at hand the
following statements may be made.

The wall-rock was not an important factor in determining the position
of the ore-shoots, if indeed it had any influence. This is inferred because
there is apparently no difference in its composition near the shoots from
that bordering barren portions of the veins.

Cross fissures are not common. In places, slightly inclined fissures
are filled with ore near the main shoot; but the condition is not so general
as to indicate that these fissures were a determining factor in the location
of the shoot.

Dykes parallel some of the veins, now on one wall, now on the other,
and are cut by them. One large cross dyke has been recently shown to
cut through the property, but whether or not it has influence on the ore
deposition has not been determined (See Figure 1, Rocher dyke).

The gangue does not appear to have exerted a deciding influence, for
the ore is found in varying amounts in all the gangues apparently without
discrimination, except that actinolite is found in all the important shoots,
mixed with the apparently solid sulphides and more or less replaced by
them.

Two major periods of fissuring, parallel to the veins and expressed in
the veins, have been demonstrated and they have an important bearing
on the location of the ore-shoots.

The primary fissuring was followed by an alteration of the brecciated
and ground-up country rock along the fissures, together with a consider-