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Mines - Portland Canal
The Gypsy, Little
Joe, and Lucky Seven Crown-granted claims were
located in 1906 along the south slope of Glacier Creek about
4 miles north of Stewart. A 40-foot shaft was sunk on a mineralized
quartz vein by the owners Beaton and Didsdale, which reportedly produced assays of $30 to $40 per ton in gold, 20
ounces per ton silver, and 20 per cent lead. Portland Canal Mining Co. Ltd.
acquired
the original claims as well as nine more in 1908. Two adits were driven and a third,
No. 3 tunnel, was projected at elevation 2,400 feet as the main haulageway.
After some feasibility
studies, a 75-ton concentrator an aerial tram-line from the Dunwell mill-site
were constructed in l9lO. A short spur-line from the Portland Canal Short
Line
Railway was laid to the concentrator and the wagon-road to Stewart improved.
 In October, 1911, the mine and
mill ceased operations after treating 7,000 tons of gold-silvet-lead ore from which about 1,500 tons of concentrates was
shipped. The ore apparently averaged 0.12 to 0.3 ounce gold; 5 to 25 ounces silver
per ton; 2.5 to 12 per cent lead, and minor variable zinc with an average value of
$12 per ton at that date.
Negligible work has been done on
the property since 1912, although Portland Canal
Terminals Limited drove a tunnel 3,629 feet long eastward from 50 feet
in elevation
above the Dunwell mill-site to intersect the Portland Canal Fissure and
to investigate
various known vein systems such as the Portland Canal vein.
This tunnel and
ancillary development on vein intersections which was completed in 1914 has
been
mainly used to carry water for the Dunwell mill. In 1954, Cassiar
Consolidated cleaned out the tunnel, which was filled with gravel, but
since then the adit portal
has caved.
In 1968, Granduc Mines, Limited,
reopened and mapped the No. 3 Portland Canal
tunnel at 2,400 feet elevation for mapping and sampling. Vein
mineralization on the property lies within thin-bedded dark Bowser graphitic
siltstones and greywackes which overlie Hazelton volcanic epiclastics.
The sedimentary rocks have been
intensely folded and deformed and intruded by a number of plutons and dyke swarms. The veins have been injected into
extensive fractures localized near the Bowser-Hazelton contact and apparently
controlled by underlying intrusions. This fracture system, which included the known
vein mineralization, was referred to as the Portland Canal Fissure Zone in
old publications.
Two oreshoots averaging 5 feet
wide, were mined from the quartz-breccia vein
which averaged 8 feet wide and was traced on surface for about 2,000
feet. Both
oreshoots were essentially flat-lying pods confined to narrow portions
of the main
vein. Sulphide mineralization in the quartz breccia consisted primarily
of pyrite,
with galena and minor sphalerite.
Like other similar veins in this
zone, the vein has a sinuous swelling shape and is cut or bounded by later, narrow, hornblende diorite (lamprophyre) dykes.
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