17

Richfield formation on the northeast side of the fold has been further
subdivided into five members, listed below:
Baker member. Fissile and non-fissile, soft, grey, limy quartzite; limestone
Rainbow member. Fissile and non-fissile, interbedded argillite and quartzite;
limestone
B.C. member. Black argillite

Lowhee member. Fissile and non-fissile, grey quartzite; limestone
Basal member. Black argillite

These members hold most of the gold deposits of value and the Rainbow
member is the most important.

The mineral deposits are of two types:

(1) Gold-bearing pyritic quartz veins

(2) Gold-bearing pyritic replacement deposits

There are four classes of quartz veins.

(1) Large veins in earlier faults practically parallel to the strike and
dip of the strata. These are not numerous and have been only slightly
developed.

(2) Lenticular veins parallel to the strata. These are not numerous
and have been only slightly developed.

(3) Transverse veins crossing the strata roughly at right angles.
These are very numerous and many are of commercial value.

(4) Diagonal veins striking north 70 degrees east to east. These are
second in numerical importance and many are of commercial value.

The known valuable veins are almost entirely in the Rainbow member.
The pyrite replacement deposits are in limestone beds in the Rainbow
member and in the lower part of the Baker member. One replacement
deposit is of considerable commercial value.

The possibilities of the belt can be considered under as many heads
as there are types of ore-bodies.

The transverse veins are in general 150 feet or less in length and 4
feet or less in width. Many are known to be of commercial value in the
two mines of the district and none has been adequately exposed except in
these two mines. The diagonal veins are in general a little wider and longer
than those of the transverse type but are less numerous. The two main
types have furnished nearly all of the ore taken from the Cariboo Gold
Quartz mine to date. All of the ore from the mine has come from the
Rainbow member. The rocks of this member are such, however, as favour
short veins and, consequently, individual veins are rapidly worked out.
The underlying B.C. member favours veins that are longer and wider.
This member should, therefore, be explored near known ore-bodies along
the strike of known zones of fracture with the hope of finding veins both
valuable and persistent.

Workings in the Cariboo Gold Quartz mine are extensive enough to
show that fractures occupied by commercial veins are in the main in
several groups or zones. Individual veins in a group may not go far along
the strike or dip, but others take their place and so far as is known
there is no diminution in the number or size of veins from the surface to
2 depth of 600 feet. The surface, 1,200, and 1,500 levels at the mine show