a
‘ane
a
‘e
jit
fi

| En

¥
uy
% ae
oF
Ft
Big
it

108

syncline with limbs dipping at angles as high as 70 degrees; the syncline pitches
to the southwest at an angle of 30 degrees. The total area of ir on-bearing forma-
tion exposed is about 250 acres. The hematite, which also occurs in cavities and
along fracture planes, varies from hard blue to soft red, but was not found in
economic quantities. : ;

Fragments of iron ore up to 15 pounds in weight are found at a number of
points on Steepbank and Moose rivers, tributaries of the Athabaska, and at a
point on Steepbank river 4-9 miles from the mouth there is a compacted bed
1 ito 2 feet thick made up of fragments of siderite weighing up to 20 pounds.
The bed is overlain by a thin capping of bituminous sand and is underlain by a
bed of clay 1 to 4 feet thick, which rests upon Devonian limestone. A represen-
tative sample of the iron ore was found to contain 35 per cent of iron and 18
per cent of insoluble matter. So far as observed the deposit has no economic
value.” :

Keele® reports hematite as occurring on Gravel river about 10 miles below
the mouth of Natla river. “This iron is coarsely laminated with red siliceous
slate, having a thickness of from 50 to 100 feet, and is interbedded between the
conglomerate and dolomite. An assay of an average sample of this ore was
made at the assay office of the Mines Branch, and gave only 25 per cent of iron.”

Thin bands of limonite, the thickest of which is only 10 inches, occur in a
section of 120 feet of shale exposed on a large stream entering the east side of
Mackenzie river 5 miles above the Ramparts. On the southern slope of Bear
mountain there is a series of reddish gypsiferous shales 30 feet or more thick.
A bed of drab clay shale, which follows the red shale, carries near the top a
band of limonite one foot thick. :

A bed described as hematite occurs in a sedimentary formation about 20
miles east of the Mackenzie near the eastern end of an Indian trail that leaves
the Mackenzie at the mouth of a ravine one mile north of Wrigley. It occurs
on the east face of the most easterly range of the Rocky Mountain system. The
section of rocks in which the hematite occurs, measured in descending order, is
as follows:

‘ Feet

Red quartzite and sandstone (summit of mountain) (dip 10°
LORD OS WSL) ee eee oe he ee ee ot 500+

Red shale and ferruginous sandstone.. .. .. ..... .. .. .. 50
PIGMOGIUO igri. a dehy ee Bee Ph Sk ut ee e 210
Red sandstone with high percentage of iron.. .. .. .. .. .. 50
Dark shales Tis. (ise ts. Dome ee a ats! 1510)
Grevyish: to Wah Snale on she ae Osa tenn notes ct he aL 225

A sample composed of average samples taken from four different levels in
the 20-foot bed was found on analysis to contain 12 per cent of iron:

Very probably the ferruginous band has a considerable areal distribution and
is brought near the surface in the northerly and southerly extension of the
mountain range. Fossils were not found in immediate association with the
bed, but it appears to lie within the limits of the upper Silurian’

A vein carrying fibrous, botryoidal, and micaceous hematite is found at
Rocher Rouge, McTavish bay, Great Bear lake; and on some of the more
southerly of the group of islands known as Les Iles du Large, Great Slave lake,

1 Alcock, F. J., Geol. Surv., Can., Sum. Rept., 1916.

2 Ells, S. C., Mines Branch, Dept. of Mines, Can., Sum. Rept., 1914, p. 63.

8 “A reconnaissance across the Mackenzie mountains on the Pelly, Ross, and Grave!
rivers, Yukon and Northwest Territories,” p. 50.

4 Kindle, E. M., Geol. Surv., Can., Sum. Rept., 1919, pp. 1-2 C.-