152

one locality is 1 foot, at a second, 2 feet, and at the third, 3 feet. If it be
assumed that the three outcrops occur at the same horizon, then it follows
that at this horizon, in a distance of 1,800 feet, the ore is first exposed with
a thickness of 3 feet and rapidly in a length of 6 feet dies out, is developed
again some distance farther north where at one place it is 2 feet thick,
and still farther north it is 1 foot thick. An iron ore-body of such dimen-
sions if it were developed in unfaulted ground would not pay to mine.
But at two of the outcrops the ore is unmistakably faulted and there is
presumptive evidence that it is faulted at the third locality. In such
circumstances, the cost of mining would be further increased.

Possibly the bed or beds increase notably in thickness along the
strike or dip of the strata or in both directions, but unless cogent reasons
are forthcoming for strongly indicating a probable not a possible material
increase in thickness, costly exploratory work necessary to decide the
question would be unwarranted. Faults occur at the ore outcrops and
presumably other undetected faults occur. Rock exposures are few in
numbers and quite insufficient to determine the structure with sufficient
exactness. Unless the structure is known beforehand any exploratory
work undertaken might produce negative results only. To determine
the structure beforehand in the general absence of rock exposures would
involve much stripping and trenching which of itself might prove costly,
for the drift cover is quite thick in places.

Prospecting might be carried on along the strike of the strata in the
hope that somewhere in that direction the ore might be developed in
greater volume. It is reported that ore occurs several miles up Sand creek
on the eastern side of the valley, but no precise information was forth-
coming regarding the location or character of the alleged discovery. It
seems possible that rust-stained strata or slightly ferruginous beds may

have been found and thought to mark the occurrence of an important ore-
body.

CARIBOO MINING DIVISION

(43) Finger Lake, Iron Mountain Group
Source of Information. Galloway, J. D.: Ann. Rept., Minister of Mines, B.C., 1921, pp. 110-111.

GENERAL DESCRIPTION

“An occurrence of hematite iron ore in the vicinity of Finger lake
was found to be much smaller than had been expected and
; the showings are not particularly promising. The showings
are situated on a small hill on the north side of Finger lake :
about 40 miles from Vanderhoof. . . . The iron ore occurs as hema-
tite and specularite in sheared zones. . . . The rock week
exposed on Iron mountain consists entirely of volcanic rocks. . . .
In . . . . zones small stringers and bunches of hematite have been
deposited, apparently by replacement action. The stringers of solid
hematite are only a few inches wide . . . . in addition there is a
certain amount of disseminated ore. . . This material
ee ou in widths up to 2 or 3 feet, but is not continuous for any gre: at
engthe 4 3s