14

be said to be characteristic of the tetrahedrite of this ore. The amount of
chalcopyrite in the ore is very small, and little can be seen besides the
small blebs mentioned as occurring in the tetrahedrite. Galena is more
abundant but does not equal in amount the tetrahedrite or zinc blende.

The paragenesis is clearly shown to be as follows:

Table of Paragenesis of the Ores of the Rocher De Boule Mine.

First mineralization
Granodiorite
Fissuring
Sericite and chlorite formed in crushed zones
Development of actinolite
Silicification
Second fissuring
Magnetite
Pyrite and arsenopyrite
Molybdenite
Pyrrhotite and chalcopyrite
Second mineralization
Arsenopyrite and pyrite
Zinc blende
Tetrahedrite
Chalcopyrite
Galena
Last phase
Development of siderite and veining by calcite
Products of oxidation
Actinolite is an important gangue mineral which in some sections appeared to come in after
the silicification and before the crushing, in others later than the first chalcopyrite.
The conspicuous absence of pyrrhotite, molybdenite, and hornblende in the second mineraliza-
tion would seem to indicate that the temperature of deposition of the second was much lower than
that of the first mineralization.

\probably sometimes contemporaneous

}otten reversed

DELTA PROPERTY. General Statement. The property of the Delta
Copper Company immediately adjoins that of the Rocher De Boule
Company (See Map 1732) and extends for about 3,500 feet east. It is
on the north side of Juniper creek, and extends from the creek bed up
to over 7,000 feet in altitude.

Description of Main Veins. General. There are a number of veins
on this property, but only two have received much attention up to the
present. The lower of these two is thought to be a continuation of the
fissuring on the upper part of the Rocher De Boule property, of which
No. 4 vein is the main expression. It outcrops at intervals along the
hillside between 5,500 feet and 6,000 feet elevation, and has been traced
from one end of the property to the other. The strike of this vein is north
85 degrees west, and its dip is 70 degrees to the north. The upper vein
outcrops at intervals across the property between elevations 6,200 and
6,700 feet. It strikes north 78 degrees west and dips 75 degrees north.

The Lower Vein. The lower vein varies in width from 2 to 3 feet at
the east end of the property where a short tunnel is located at 5,900 feet
elevation. A sample taken from across 20 inches gave the following values:
gold, trace; silver, 0-5 ounce per ton; copper, 1-5 per cent. Two hundred
feet west, at the McDonell cut (See Figure 3), the vein is 4 feet wide with
2 feet of low grade ore. Two thousand feet. to the west of the tunnel,
stripping shows a vein 8 feet in width with 23 feet of magnetite, hematite
mostly, and some chalcopyrite, assaying—gold, 0-01 ounce; silver, trace;
copper, 1-10 per cent. The remaining 5-5 feet is of decomposed material
which assayed: gold, 0-01 ounce; silver, 0-40 ounce; copper, 0-14 per cent.
A very fine exposure of ore was “opened near the last-mentioned stripping,