Metallogenesis and Tectonics of the Russian Far East, Alaska, and ...

Rossland Metalogenlc Belt of
Au-Ag Polymetallic Vein Deposits
Belt RL) Southern British Columbia
The Rossland m~Uogmic belt of Au-Ag polymetallic vein deposits (fig. 49; tables 3,4) occurs in southem Eltiti&
Columbiak host4 in or near granitoid pluions of the Middle Jurassic Nelson Plutonic Suite. This granitic suite represents the
oldest continental-margin an: in lhe Canadian Cordillera. The plutons and vein deposits intrude the QuesneDa, Kootenay, md
Cassiar terranes, and the No& Ameaican Craton Margin (Hoy and Dunne, 1992; H0y and Andrew, 1988). The significant
deposits in tbe belt are at RossW Camp (Le Roi, War Eagle), Sheep Creek (Kootenay Belle), and Ymir-Erie Creek (Ymkee Girl;
table 4) moueberg and others 1997a, b, 1998).
Rossknd Au-Ag PolymetJlis Vein Cmp
The Rosflarrd Au-Ag polymetallic vein camp (fig. 60) occurs in three areas, the North belt, Main veins, and $ouh belt.
Most production (>go%) has been from the Le Roi, Center Star, Nickel Plate, War Eagle, and Josie mhs which occur in he Main
vein system (Dawson ad others, 1991; Schroeter and Lane, 199 1; Hoy and Dunne, 1992; MINFILE, 2002). The Main vein
deposits consist of pynhs~ite and chalcopyrite in a gangue of quartz and calcite with an average ore grade of 1% Cu. The
pyrrhotite-ehakopyntc veins arc located along the margins of the intrusions, are disseminated and rt~sociatd wilh K and Si skarn
alteration at deep levels, grade to massive veins wilh minor gangue and alteration envelopes at higher levels, and in uppermost
levels, brittle fracture-wntr~ikd veins with Pb-Zn-Ag and quartz-carbonate gangue predominate. The veins in the Main vein
system form an en-echelon set which occurs betwm two large north-trending lamprophyre dikes. Tbe veins dip steeply north and
strike 070". A struchtml control is inferred by growth faults which were active during deposition of Ro~land Group. Total
production from Rosslaod Camp between 1894 and 1941 was 7.62 million tonnes of ore grading 15.2 g/t Au, 19 g/t Ag, resulting
in extraction of 84 tonnes of Au ad 105 tomes of Ag. The timing of vein emplacement with respect to the phtvns in the district
is not known precisely (Files, 1984; Hoy and others, 1998).
MiddeEoam LOYYI# and -7) JUassic Pennsylvanian 8 Permian / W vdns
--
a~orydh4r-m r.'J &dmd h&mzode R(ount Roberta Fanration A Thm Surrassic a Fs m y -
El
Figure 60. Rossland Au-Ag polymetdk vein and related deposits, Rossland metallogenic belt, Canadian Cordillera Schematic
geologic mep. Adapted from Hoy and Andrew (1 988).