6

yet known in the Rockies in British Columbia. Bedded, ferruginous strata
appear to be absent from the Precambrian and later strata, unless the
Sand Creck occurrence is of sedimentary origin. 4 é

Along the western flanks of the Rocky mountains, Precambrian sedi-
ments are intermittently displayed, but west of the Rocky Mountain trench
strata of this age are broadly developed and in the south extend west
beyond Kootenay lake. These measures over wide districts appear to be
lacking in any strata even remotely resembling bedded iron ores, but south
of Nelson, close to the International Boundary, near Salmon river (locality
38), a thin bed of magnetite occurs in the sedimentary strata and may be
a ferruginous sediment. Also near Crawford bay (locality 39) on the east
side of Kootenay lake, hematite occurs associated with sedimentary rocks.
These two occurrences represent the only known possible examples of
sedimentary iron ores throughout the interior of British Columbia.

In northeastern British Columbia, where the province extends east-
ward into the region of Cretaceous sediments bordering the Rocky moun-
tains on their eastern side, certain horizons in the Cretaceous beds are
characterized by coneretionary masses of clay ironstone. It is not incon-
ceivable that in places beds of considerable lateral extent may be rich
enough in iron to warrant being designated low-grade iron deposits,
but no such deposits have yet been found there nor in the eastward and
southward extension of the Cretaceous rocks in Alberta where, in places,
similar nodular, ferruginous bodies are abundant. In the Cretaceous beds of
eastern Vancouver island, on Sable river (locality 23), a thin bed of clay
ironstone has been found and this is the only known example of sedimentary
iron ore occurring with any of the stratified rocks of the regions along the
Pacific coast of the province.

All available evidence seems to indicate that British Columbia lacks
any extensive, bedded, iron formations or any valuable sedimentary
iron ore deposits except, possibly, the limonite or bog iron ore deposits.
The limonite ores occur in deposits of considerable extent in various locali-
ties, as on Zymoetz river (locality 1), Taseko river (locality 29), and at
Alta lake (locality 25) in the western part of the province, and near Nicola
lake (locality 32) in the southern interior. What appear to be less import-
ant deposits occur elsewhere also. All the limonite deposits that have
been closely investigated have been found to have been produced by
springs which derive their iron content from pyritiferous strata, or, as in
the Peace River country (locality 44), from nodular clay ironstone in Creta-
ceous strata. These deposits, so far as known, are all of Recent age,
for they naturally occur in relatively low situations and any that existed
in Tertiary time rarely, if ever, escaped destruction during the Glacial
period. The requisite conditions for the production of limonite bodies
doubtless exist in many parts of central and western British Columbia
and the total amount of limonite may be great, but large, single deposits
are exceptional and not the rule. Their mode of formation is such that
individual deposits or groups of deposits may have a very considerable
areal extent, but the deposits are always comparatively shallow and the
content of the individual bodies usually is disappointingly low.

_ In Yukon territory, in Mackenzie mountains, and in Ogilvie moun-
tains which extend westward from them towards the Alaska boun-
dary north of Yukon river, there are indications of the existence of one
or more sedimentary iron-bearing formations. Fragments of banded,