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CHAPTER IiTt

IRON ORE OCCURRENCES IN YUKON TERRITORY AND IN
BRITISH COLUMBIA EXCLUSIVE OF WESTERN
VANCOUVER ISLAND

YUKON

(1) Tatonduk River and Cathedral Creek

Source of Information. Cairnes, D. D.: ‘“The Yukon-Alaska International Boundary vetween
Porcupine and Yukon Rivers’’; Geol. Surv., Canada, Miem. 67, pp. 44-45, 112 (1914),

GENERAL DESCRIPTION

A group of not greatly deformed nor highly metamorphosed sedimen-
tary strata with associated volcanics, known as the Tindir group, occurs
at intervals between Porcupine and Yukon rivers in the vicinity of the
International Boundary. The Tindir group is considered to be older
than Middle Cambrian and may be Precambrian. The strata are largely
oe but include beds of limestone; they are several thousand feet
thick.

Regarding certain, possibly local, developments of the Tindir strata,
Cairnes? writes as follows. ‘Iron containing minerals, chiefly hematite,
magnetite, and their oxidation products, comprise a considerable percentage
of some of the beds of the Tindir group to the south of Cathedral creek.
In places, limited portions of these deposits occurring in beds ranging from
2 to 10 feet in thickness, contain up to 30 per cent or even 40 per cent
metallic iron. Also, on a small tributary of Tatonduk river flowing into
it from the north, certain peculiar reddish conglomerates resembling
consolidated boulder clay . . . - contain considerable hematite in
places. Limited portions of this conglomerate appear to contain from 5
per cent to 25 per cent metallic iron. A few local seams also outcrop in the
dark shales . . . . exposed along Tatonduk river in the vicinity of
the boundary line, but none were noted having a thickness exceeding 2
inches.”

These beds of low-grade iron ore are presumably of sedimentary
origin and if so they may characterize particular horizons within the
Tindir group and, possibly, in places may form comparatively thick beds
of relatively high-grade iron ore. Strata resembling the Tindir beds have
been recognized far to the east in Ogilvie mountains and it may be
that the hematite and magnetite of Hart, Wind, and other rivers (See
immediately succeeding descriptions) come from Tindir beds.

1By G. A. Young.
2Op.cit., p. 112.
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