Lay, D. (1936): Pre-Mississippian veins and deposits of the Cariboo—The Miner, Vol.
9, No. 1, Jan. 1936, pp. 27, 28.
Lay, D.; LANG, A. H.; and Others (1938): Cariboo number—The Miner, Vol. II,
No. 8, Aug., 1938.
MAPS.

Geological with Marginal Notes.
Cariboo Mountain, Map 5634—Dept. of Mines and Resources, Ottawa, 1940. Scale,

4——slemnie

Chiaz Creek, Map 5644—Dept. of Mines and Resources, Ottawa, 1940. Scale,
1/G—s lms ;

Keithley Creek, Map 562A—Dept. of Mines and Resources, Ottawa, 1940. Seale,
A— emis

Little River, Map 561A—Dept. of Mines and Resources, Ottawa, 1940. Scale, 1” = 1 mi.

Willow River Sheet (West Half), Map 335A—Dept. of Mines and Resources, Ottawa,
1938. Scale, 1” —1 mi.

Willow River Sheet (East Half), Map 336A—Dept. of Mines and Resources, Ottawa,
1OB8asascales 144—— emir

Placer Creeks.

BowMan, A. (1895): Maps of the principal auriferous creeks in the Cariboo, Maps
364-372—Geol. Surv., Canada, 1895.

Topographical.

Quesnel Sheet, Map 3G—B.C. Dept. of Lands and Forests, Victoria, 1935. Scale,
1 8} eal,

HOBSON CREEK.*

Gold mineralization has been found on the summits between the headwaters of
Hobson Creek and Azure River. The first discoveries were made about 1914; since
then there has been a small amount of development but no production. The region is
extremely rugged, with ice-capped peaks rising to elevations of more than 8,000 feet.
The known showings can be reached by two routes: from Gosnell on the C.N.R. by 45
miles of trail up the North Thompson River valley and across a high pass to Azure
River, or by about 18 miles of trail up Hobson Creek from Hobson Lake. <A third
possible route is up the Raush River, about 50 miles up from its mouth, near McBride;
but a trail built some years ago is now largely obliterated.

The rocks are Precambrian sediments, being chiefly quartzites, but including
phyllites, argillites, and one or two bands of limestone. The rocks are compressed
into north-westerly-trending folds, but, as at the head of Azure River, there is some
complex folding and perhaps major faulting. A body of granodiorite cuts these rocks
about 2 miles south of the known mineralization.

The mineral deposits include quartz veins and replacement deposits in limestone.
The veins are irregular and tend to be lenticular, but follow a clearly recognizable
pattern in most instances. Where a stockwork or intersecting pattern of quartz veins
occurs, the higher values are found to favour one direction of fracturing. At the head
of Hobson Creek (Blue Ice property) the vein pattern is similar in general to that in
the producing mines in the Cariboo, but the impure quartzites are less schistose.
At the same locality there are replacement bodies of pyrite in a band of limestone. In
the quartz veins there has been proved in a few instances an association of gold with
sphalerite and galena, even though the amount of these minerals is extremely small.

In some parts of the area the size of the quartz veins varies greatly with the
character of the wall-rock; this is particularly noticeable where the rocks are inter-

* By M.S. Hedley.

18