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File Created: 24-Jul-85 by BC Geological Survey (BCGS)
Last Edit:  31-Jan-08 by Laura deGroot(LDG)

Summary Help Help

NMI 092F12 Zn1
BCGS Map 092F052
Status Past Producer NTS Map 092F12E
Latitude 49º 34' 03" N UTM 10 (NAD 83)
Longitude 125º 36' 18" W Northing 5493805
Easting 311648
Commodities Copper, Zinc, Lead, Gold, Silver, Cadmium Deposit Types G06 : Noranda/Kuroko massive sulphide Cu-Pb-Zn
Tectonic Belt Insular Terrane Wrangell, Plutonic Rocks
Capsule Geology

The Myra Falls Operation includes the Lynx (092F 071), Myra (092F 072), Price (092F 073) and H-W (092F 330) deposits and associated zones. The Lynx volcanogenic massive sulphide deposit occurs within the southern part of the Buttle Lake uplift. This discreet belt of northwest striking Upper Paleozoic rocks is bounded on the east by Upper Triassic Karmutsen Formation volcanics (Vancouver Group) and on the west by the Early to Middle Jurassic Island Plutonic Suite. The geology of the uplift has recently been reinterpreted and the stratigraphy has been reassigned to several new formations of a redefined Sicker Group and the new Buttle Lake Group (formerly the upper part of the Sicker Group), (Juras, 1987; Massey, Personal Communication, 1990).

The Buttle Lake Group consists of: (1) the Lower Permian(?) Henshaw Formation composed of conglomerate, epiclastic deposits and vitric tuffs; and (2) the Lower Permian to Pennsylvanian Azure Lake Formation (formerly Buttle Lake Formation) consisting of crinoidal limestone and minor chert.

The Sicker Group consists of: (1) the Mississippian(?) or Pennsylvanian(?) Flower Ridge Formation largely comprising coarse mafic pyroclastic deposits; (2) the Lower Mississippian(?) Thelwood Formation, a bedded sequence of siliceous tuffaceous sediments, subaqueous pyroclastic deposits and mafic sills; (3) the Upper Devonian Myra Formation consisting of basaltic to rhyolitic flows and volcaniclastic rocks, lesser epiclastic sediments, argillites and cherts, and massive sulphide mineralization; and (4) the Upper Devonian or older Price Formation comprising feldspar-pyroxene porphyritic andesite flows, flow breccias and minor pyroclastic deposits.

The Buttle Lake uplift stratigraphy indicates deposition in a rift basin in an island arc environment. It has been intruded by granitic dykes related mainly to the Island Plutonic Suite. A 1- kilometre wide stock of Tertiary intrusives lies about 1 kilometre to the east. This stock (formerly called Catface Intrusions) is related to the new Mount Washington Intrusive Suite of Late Eocene to Early Oligocene age (Nick Massey, Personal Communication, May 1990).

The major occurrences in the Buttle Lake area lie along a northwest striking, 65 degree southwest to steeply northeast dipping zone that is approximately 6 kilometres long. The rocks have been metamorphosed to the lower greenschist facies, and have been deformed along northwest trending subhorizontal open folds. Several regional, west-northwest to north trending faults occur with maximum lateral displacements of about 850 metres. The faults are considered to be post-Mesozoic, and are probably related to Late Cretaceous uplift. The contact between the Myra Formation and the overlying Thelwood Formation is marked by a 2 to 40 metre wide zone of strong schistosity that may represent an Upper Paleozoic low angle fault.

The Myra Formation, dated at 370 million years (Juras, 1987), contains intermediate to felsic volcanics, volcaniclastics, minor argillite and is host to the massive sulphide horizons. The Lynx, Myra (092F 072) and Price (092F 073) deposits lie at the same stratigraphic level as the Myra Formation (the "Mine Sequence" of Juras). The H-W deposit (092F 330) lies below them at the base of the Myra Formation. Westmin Resources' Myra Falls Operations has developed these deposits as four mines. In 1990, the Lynx and H-W mines fed a 4000-tonne per day mill, the Myra mine is depleted and the Price deposit has yet to be used as a source of mill feed.

The major ore zones of the Lynx mine are the G, S, South Wall and the West G zones, all of which are located within an area of 2.5 by 0.7 kilometre.

The massive sulphide horizon lies within a zone of quartz- feldspar rhyolite tuff and minor chert. This tuff is underlain by dacite flow breccia and tuff. The breccia includes clasts of H-W mineralization, andesite flows, the rhyolitic H-W horizon, and the Price Formation. Rocks in the feeder zone below the massive sulphide horizon have undergone sericitization and silicification. Pyrite alteration is evident from disseminated pyrite and pyrite stringer zones.

Overlying the massive sulphide horizon are pillow basalts, mixed pyroclastics and tuffs, felsic rhyolite and flow breccia, all of which are overlain by the Thelwood Formation.

The lenses of massive sulphides occur in a gangue of quartz, sericite, chlorite and talc, and comprise chalcopyrite, galena, sphalerite, pyrite and pockets of barite. Minor tennantite, bornite, pyrrhotite, digenite, covellite and stromeyerite are present. The lenses are up to 12 metres thick and 244 metres long, pinching out along strike.

A significant new discovery of massive sulphides (Gap zone) located underground between the H-W and Lynx mines is believed to be in upper H-W mine stratigraphy. See H-W (092F 331) for further information.

The Lynx occurrence was mined by open pit methods from 1966 to 1976, then by underground mining techniques to the present. Between 1967 and 1988 (inclusive), combined milled production of the Lynx/Myra/H-W Mines totalled 9,162,835 tonnes containing 15,205,759 grams of gold, 615,419,293 grams of silver, 153,750 tonnes of copper, 56,670 tonnes of lead, 525,606 tonnes of zinc and 1,348 tonnes of cadmium (Mineral Policy data).

According to Westmin Resources Annual Report for 1988, up to the end of 1988, the Lynx mine contributed 53.8 per cent, or 4,933,790 tonnes, of a total of 9,170,609 tonnes milled at the Myra Falls Operations. The overall grade of the total ore milled was 2.16 grams per tonne gold, 81.0 grams per tonne silver, 1.83 per cent copper, 0.78 per cent lead and 6.58 per cent zinc. During 1988, the Lynx mine contributed only 9.5 per cent of all ore processed at the mill, the bulk coming from the H-W mine (Westmin Resources Limited Annual Report 1988, page 8).

Proven and probable geological reserves at the Myra Falls operations as of January 1, 1993 are:

Name Tonnes Grades
Gold Silver Copper Lead Zinc
g/t g/t % % %
H-W Mine 8,955,100 2.2 39.6 1.7 0.4 4.3
Lynx Mine 315,300 3.0 94.0 1.7 1.1 10.0
Price Mine 185,000 1.5 66.4 1.4 1.3 10.4
Gap Zone 634,400 3.2 151.5 1.8 1.1 13.3
Battle Zone 2,013,700 1.1 24.2 2.6 0.5 12.7
Extension (W37) Zone 231,100 1.2 60.4 1.7 0.4 3.8
Trumpeter Zone 61,200 3.2 68.9 6.3 0.3 4.6
6 Level 120,500 1.3 91.4 0.4 0.9 6.0
Total 12,516,100 2.1 45.6 1.9 0.5 6.3

Compiled from George Cross News Letter No. 30 (February 12), 1993. Westmin plans to drill the Marshall zone (discovered in 1993) from 10 level in the Lynx mine and it has started to drive an 800-metre crosscut to provide access. The company completed the first 400 metres in 1997. It will complete the remainder and start drilling in 1998. Elsewhere on 10 level, the company completed five diamond-drill holes (aggregate depth of 3505 metres), looking for detrital sulphide in fine-grained sediment in a local palaeotopographic depression between the H-W and Ridge zones. The holes intersected sulphide; however the results were erratic and grades inconsistent.

Resources in the Marshall zone, situated on the H-W horizon, stand at 320,000 tonnes averaging 7.6 per cent zinc, 0.7 per cent copper, 0.7 per cent lead, 2.5 grams per tonne gold and 105.6 grams per tonne silver. The zone remains open to the east, west and to the north (Northern Miner, June 28, 1999).

EM EXPL 2000-25-32; 2001-23-31; 2002-29-40
EMPR AR 1918-268; 1919-220; 1920-207; 1921-222; 1922-241;
1923-254,388; 1925-283; 1927-349; 1928-378; 1929-384-385; 1930-
301; 1952-211; 1961-103; 1962-107-110; 1963-105; *1964-157-166;
1965-234; 1966-77; 1967-A52,77,78; 1968-A52,105; 1969-A53;
1970-A52; 1971-A52; 1972-A52; 1973-A52; 1974-A118; 1975-A92;
1976-A102; 1977-114; 1978-126; 1979-129
EMPR ASS RPT 459, 533, 607, 5184, 7089, 7090
EMPR ENG INSP Annual Report 1989, 1990
EMPR EXPL 1978-E130; 1979-133; 1996-A9,F5; 1997-56; 1998-5,48
EMPR GEM 1969-218,426; 1970-284,479; 1971-26,252; 1972-22,271;
1973-24,235; 1974-25,181
EMPR INFO CIRC 1997-1, p. 8; 1998-1, p. 9
EMPR IR 1984-2, pp.99,100; 1984-3, pp.105,106; 1984-4, p.20; 1984-5,
pp.113,114; 1986-1, pp.109,110
EMPR MAP 65 (1989)
EMPR MIN STATS 1995, pp.47,48; 1987, pp.35,37; 1990, pp.25,29,32;
1980-1994, pp.20,24
EMPR MINING Vol.1 1975-1980, pp.1-2,53,58,62,65,68,72; 1981-1985,
pp.2,30; 1986-1987, pp.44-45; 1988, pp.41-42
EMPR OF 1992-1; 1998-10; 1999-2
EMPR P 1987-1, p. 223; 1988-1, p. 81; 1989-1, p. 75; 1991-4, pp.
EMPR PF (Granby Consolidated Mining, Smelting and Power Company
Limited (1952): Lynx and Paw Groups, 1:3600; Photographs; Western
Mines (1961): Geology and Drill Holes, 1:480, Sections 1:240 DH
W5-10, DH W11, DH W8-W9, DH W7, DH W1; Various Correspondence and
Letter Reports in Lynx (092F 072); Jeffery, W.G.(1963):
Preliminary Map, 92F12; Various maps and reports in 092F 072
(Paramount) and 092F 073 (Price); Jeffery, W.G. (1964): An
Assessment of the Economic Mineral Potential within a Part of
Strathcona Provincial Park; *Jeffery, W.G. (1970): Buttle Lake;
Geological Map, 1:31,680; Property Ownership, 1:50,000; Western
Mines Limited (1974): Expanded Composite Showing Underground
Development, Plan (1), Lynx Mine, 1: 1200; Western Mines, Geology
12 Level, 1:1200; Various Correspondence on Strathcona Park;
Eastwood, G.E.P. (c.1975): Mineral Resource Considerations Raised
by Proposed Changes to Strathcona Park - Conclusions and
Recommendations; *Westmin Resources Limited Annual Report 1988 (in
Debbie (092F 079) file; Pearson, C.A. (1992): New Ore Discoveries
at Myra Falls Operations, Buttle Lake, Vancouver Island, BC, CIM
District 6 Meeting, October 1-3, 1992, Campbell River, BC in H-W,
092F 330; GSA Field Trip 1985, Westmin Resources' Massive Sulphide
Deposits, Vancouver Island, Trip 1; Geology notes from CIM 1981; S.D. McKinley (2002): Evolving Geological Models at the Myra Falls VMS Camp, Vancouver Island, BC: An Update and Examples from the Marshall and Ridge Zone, presented at Geology of Base Metals - CIM Vancouver 2002)
EMR MP CORPFILE (Western Mines Limited)
EMR RES FILE (Paramount; Myra; Claw; Lynx)
GSC MAP 196A; 2-1965; 17-1968; 1386A
GSC OF 9; 61; 463; *2167, pp. 145-161
GSC P 66-1; 68-50; *71-36; 72-44; 79-30
GSC SUM RPT 1930 Part A, p. 56
CIM BULL Dec. 1980, pp.71-90
CIM Vol.73, No.824, p. 86; Vol.80, No.899, p. 134; Transactions Vol.
83, pp. 115-130
CMH 1976-77, p. 331; 1989-90, p. 470
CMJ Oct. 1981; Nov. 1985, Sep. 1986
GCNL #92, 1970; #214, 1971; Feb.7, #76, 1973; #35,#95,#160,#222,
1974; #87,#95,#204,#205,#220, 1975; #41,#91,#105,#218,#220,#246,
1976; #39,May 16,#87,#221, 1977; #43,#150,#217, 1978; #33,#88,#92,
#144,#186,#198,#231,#242,#246, 1979; #19,#32,#34,#54,#55,#68,#90,
#101,#108,#128,#154,#159, 1980; #152, 1982; #101,#151,#153, 1983;
#41,#103, 1984; #149, 1985; #42, 1986; #85, 1987; #88(May7),
#91(May10),#99(May23),#102(May28),#104(May30), 1991;
#24(Feb.4),#35(Feb.19), 1992; #30(Feb.12), 1993
MIN REV Fall 1998, pp. 32-33
MINING IN CANADA Mar. 1967, p. 16
N MINER MAG August 1989
N MINER Apr.26, 1973; Apr.25, 1974; May 5, Jun.2, 1977; Mar.2, Apr.20,
May 4, Aug.10, 1978; Feb.15, 1979; Feb.21, Apr.3, 1980; Apr.23, May
21, Oct.29, Nov.12,26, 1981; Apr.15,29, Nov.4, 1982; Jan.20, Feb.
17, Apr.7,21, Aug.11, Oct.20, 1983; Mar.29, May 31, Dec.27, 1984;
Feb.28, Apr.25, 1985; Aug.30, 1984; Sept.30, 1985; Mar.17, May 12,
Jun.16, Sep.1, Nov.24, 1986; Jun.1, 1987; Aug.21, 1989; May 13,
20, 1991; June 28, 1999
NW PROSP Dec. 1986; Jan. 1987
PERS COMM Hampton, R.O., Dec. 16, 1974; Massey, N., May 1990
W MINER Oct. 1963, pp.64-65; Aug. 1965, pp.37-42; Oct. 1970; May 1977
p. 62; Apr. 1978, p.122; Mar. 1979, p.46; Mar. 1980, p.60; Jun.,
Dec. 1981; Apr. 1982; Mar., *May 1983; Apr., Dec. 1984
WIN May 1987
Boliden Westmin Ltd., 1998 Myra Falls Exploration Forum, July 23-25,
Carson, D.J.T. (1968): Metallogenic Study of Vancouver Island with
Emphasis on the Relationship of Plutonic Rocks and Mineral
Deposits, Ph.D. Thesis, Carleton University
Carvalho, I.G. (1979): Geology of the Western Mines District,
Vancouver Island, British Columbia, Ph.D. Thesis, University of
Western Ontario
Hudson, R. (1997): A Field Guide to Gold, Gemstone & Mineral Sites of
British Columbia, Vol. 1: Vancouver Island, p. 164
*Juras, S.S. (1987): Geology of the Polymetallic Volcanogenic Buttle
Lake Camp, with Emphasis on the Price Hillside, Central Vancouver
Island, British Columbia, Canada, Ph.D. Thesis, University of
British Columbia
*Pearson, C.A. (1993): Mining Zinc-Rich Massive Sulphide Deposits on
Vancouver Island, British Columbia, International Symposium -
World Zinc 1993, pages 75-84
Province Feb.19, Apr.15, Nov.15,27, Dec.17, 1974
Times Colonist Aug.28, Dec.19, 1974
Vancouver Sun Apr.19, May 14,15, Aug.15, Nov.7, Dec.16, 1974
Yole, R.W. (1965): A Faunal and Stratigraphic Study of Upper
Paleozoic Rocks of Vancouver Island, British Columbia, Ph.D.
Thesis, University of British Columbia