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

Mount Sicker Metallogenic Belt of Kuroko
Volcanogenic Massive Sulfide
Zn-Cu-Pb-Au-Ag Deposits (Bett MS)
Vancouver Island
The Mount Sicker metallogenic belt of kuroko massive sulfide Zn-Cu-Pb-Au-Ag deposits (fig 17; tables 3,4) occurs in
southwestern British Columbia on Vancouver Island. The belt is hosted by the Late Devonian to Early Permian Sicker Group, a
sequence of arc-related volcanic and sedimentary strata in the southern Alexander sequence of the Wrangellia superterrane. The
significant deposits are at Mount Sicker near Duncan (Lenora-Tyee, Twin J, Lara, Copper Canyon), and Myra Falls (Buttle Lake,
Lynx, H-W, Battle; table 4) (Nokleberg and others 1997a, b, 1998).
Mount Sicker (Lenora-Tyeq Twln J, Lara,
Copper Canyon) Kuroko Massive Sulllde
Zn-Cu-Pb-Au-Ag Deposit
The Mount Sicker (Lenora-Tyee, Twin J, Lara, Copper Canyon) kuroko massive sulfide Zn-Cu-Pb-Au-Ag deposit
consists of massive pyrite, chalcopyrite, sphalerite, galena with barite hosted in Late Devonian felsic volcanic tuffs of the
McLaughlin Ridge Fomtion (Juras, 1987; Sicker Group; Hoy, 1991; Robinson and others, 1994). The combined estimated
reserves and production for the Lenora-Tyee-Twin J deposit are 594,852 tonnes grading 2.46% Cu, 3.85% Zn, 0.37% Pb, 117.0
g/t Ag, and 2.5 glt Au. Estimated reserves for the Lara deposit are 529,000 tonnes gdmg 1.01% Cu, 5.87% Zn, 1.22% Pb, 100.1
g/t Ag, and 4.73 g/t Au. Estimated reserves for the Copper Canyon deposit are 32.4 million tomes grading 0.75% Cu, 8.57 g/t Ag,
and 1.17 g/t Au (Dawson and others, 1991).
Myra Falls (Buttle Lake, Myra, Lynx, KW, Battle)
Kuroko Massive Sulfide Zn-Cu -Au-Ag Deposlt
The Myra Falls (Lynx-Myra, Price, H-W, Battle) kuroko volcanogenic massive sulfide Zn-Cu -Au-Ag deposit (fig.
24)consists of massive spbalerite, chalcopyrite, pyrite and lesser galena and barite with minor tennantite, bomite, pyrrhotite,
digenite, covellite and slromeyerite which occur in a number of lenses along an east-west trend (Juras, 1987; Juras and Pearson,
199 1 ; Dawson and others, 199 1 ; Hoy, 199 1; George Cross Newsletter no. 30, February 12, 1993; Pearson, 1993). The deposits
contain an estimated combined production and reserves of 30.3 million tonnes grading 2.23gIt Au, 54.5glt Ag, 2.12% Cu, and
7.1 % Zn. The deposit is hosted within felsic volcanics of the Late Devonian Myra Formation in the Sicker Group. The deposits
occur at two stratigraphic levels; the H-W horizon, at the base of the Myra Formation, and the Lynx-Myra-Price horizon, in the
central portion of the Myra Formation. Under the H-W deposit, the stratigraphic footwall consists of greater than 300 rn of basaltic
andesite of the Price Formation which in tensely altered to to quartz-smicite-pyrite.
Figure 24. H-W kuroko massive s~lphfde LpCbb- S b m, mm.
cross section. Adapted fmm Bwralt Md ~~~k (1-1.
Origin of and Tectonic Controls for
Mount Sicker Mdafbgwh Belt
The b k o volcanogeaic massive sulhck Za-CwPb-A+A$ dcpmls in be ?&mt Skkw meWqpk belt occur ushdylitaa
fragmental badtic mdrsitt, kw decik and rpdcsite, inripnnsttivla pillow Lavk UNI cpi~btk vulasak m& % hortrodcd
deposit distrilnttion art debmi by h e ~~ upUAs. ne voltaniG r& et 310 b 440 m thick ad &bitan U-Pb,
zlrcon isotopic age of 370 Ma ( J m , 197). Ubdedyingpih kBPLtk h w of'h PricdFermatkn farmGdduriwa nonexplosive
effusive evwt which waa wcocdal by dhg. fclric voWlm, md &jrmabim of d w flde depmistJ. Tbci
volcanic rocks arc overlain by Cbfc~.ant sedirrrrnluy rwb which mtah bioclaelic erhruidarl limmtme in the EhrttEe Ladm
Formation. Sigdinnt kuroko mwixivc wlfrde d m occur hkkc v&mLs dthe uppar p& of& wk~ CWtp C b&