141

Rocky Mountain Ranges are composed very largely of Paleozoic and
Mesozoic strata and include no known intrusive rocks, conditions that are
generally considered unfavourable for the occurrence of lode deposits.
Profound faulting along the course of the Rocky Mountain Trench may have
opened fissures along which minerals were deposited, but if so they will be
difficult to find because of the heavy drift cover. The occurrence of copper
minerals on Pesika Creek, 25 miles northeast of Fort Grahame, is, however,
proof that lode deposits are to be found, if only rarely, along subsidiary
faults, in the Rocky Mountains immediately east of the Trench.

Highly folded quartzite, argillite, and slaty rocks that outcrop south
of the Alaska Highway along the valleys of Toad River and McDonnell
Creek, and that are thought to be of Precambrian age, are probably worth
prospecting. These rocks are intruded by gabbro dykes, some of which are
50 feet wide, near the Highway. Williams (1944) has noted the presence of
quartz veins, showing brown and yellow stains, in the quartzites 14 miles
south of the Highway up McDonnell Creek. He also records an occurrence
of purple fluorite in the overlying limestone near mile 399. Small quantities
of fluorite were also seen in the limestone near the south end of Muncho Lake.

High-grade bituminous coal seams of Lower Cretaceous age constitute
the most valuable mineral resource found to date in northeast British
Columbia. The coal is found in the upper part of the Bullhead group,
which is widely exposed in the Foothills along the valleys of Peace and Pine
Rivers, and along Carbon and Fisher Creeks. ‘The formation extends
north to beyond Sikanni Chief River, but thins in that direction and is
unknown north and west of Fort Nelson.

Coal leases were acquired in the Peace River Canyon coal area as early
as 1908, by Neil Gething and associates. The Grant seam at the west end
of Grant Flat on the north side of Peace River, 15 miles west of Hudson
Hope, was the first seam to be’ actively worked. It was recorded by
F. H. McLearn of the Geological Survey in 1918, and by 1922 was opened
by an adit 360 feet long. During the summer of 1926, Peace Canyon
Mining and Transportation Company Limited shipped some coal down the
Peace by barge from Grant Flat, but this method of transportation was
found to be too hazardous and the property was closed down.

‘lding of the Alaska Highway gave a new impetus to coal mining,
and zeae the opening of four new mines, namely, Peace once ae
on Larry Creek, on the west slope of Portage Mountain; ais ae hing
mine, on the east slope of Portage Mountain, 13 miles north o ree
aoe and 12 miles west of Hudson Hope; Packwood poe oe ae Hee
spur of Butler Range, 22 miles Westact eee pore eu . cate ee zs

i § juncti
ae Chaba sia The following table shows the ame pro-
eeren of these mines during the period 1942 yr wee ‘ he seu
represent tons of coal mined and sold as reported in the Annu p
the Minister of Mines of British Columbia.