NI 1
The Pas
55 42.14'
97 55.49'
Uncertainty (m)
400 m
UTM Zone
L.S./Quarter Section
Sulphides occur in massive to stringer form, and as flow breccia, in Precambrian perioditite and biotite schist. The ore is fine-to coarse-grained pentlandite, with minor chalcopyrite, nickel arsenides and other nickel-bearing minerals.
The tabular deposit is 4 800 ft. long, 4 000 ft. wide, and 10 ft. thick (true dimensions). It strikes north to northeast, dips steeply west, and plunges north at 80. It is stratigraphically controlled near the contacts with metasediments and schists (INCO Exploration Staff, Thompson, Sept. 23, 1975).
Copper, Cobalt, Gold, Silver, Platinum, Palladium
The mine is 4 km east of Birchtree Lake and about 5 km southwest of the city of Thompson.
Pip 411 was the sight of the original discovery. The Gay and Ink groups also overlie the deposit. The following history is that of Pip 301 and Ink 6, the claims on which shafts were sunk.
Pip 301 (P 27900) was staked by A. Crait on behalf of Canadian Nickel Company Limited in 1953 and assigned to the company that same year. A geophysical survey was completed by April, 1954. Results are not known. The claim was assigned to The International Nickel Company of Canada, Limited (hereinafter INCO) in 1956 and leased as M-4842 in 1959.
Ink 6 (P 1383A) was a partial restaking of Jip 144 (P 54963). Jip 144 was staked by O. Perepeluk and assigned to Quinn-Labine Mines Limited in 1957. A magnetometer survey found a conductor on the southern part of the claim. Jip 144 was assigned to Conwest Exploration Company Limited and then to Birchtree Mines Limited in 1958. It was cancelled one year later. The dimensions of Jip 144 and Pip 301 were drastically changed when the latter claim was surveyed in 1958.
Ink 6 was staked in 1962 by J.F. Church on behalf of Canadian Nickel Company Limited and was immediately assigned to that company. It was transferred to INCO in 1962 and leased as M-7909 one year later.
The discovery of the Birchtree deposit was announced by H.S. Wingate, Chairman of the Board of INCO in his Address to Shareholders in 1964. He stated, "...the grade of the ore is good and the indicated quantity is sufficient to warrant immediate mining". Apart from this statement no other grade or tonnage estimates have been released.
The sinking of the development shaft began on Ink 6 in 1964. This three-compartment shaft was completed to 1373 ft. one year later. Between 1965 and 1967 the production shaft on Pip 301 was sunk to 2800 ft., with levels between 300 and 2300 ft. at 200 ft. intervals (INCO Thompson Exploration Staff, July 24, 1975). The two shafts were to be connected on all levels above 1300 ft. The bottom production level was 2300 ft. in 1965 (INCO Thompson Exploration Staff, Sept. 23, 1975).
Lateral development took place in the production shaft in 1966. Production commenced in 1969 at the rate of 4000 short wet tons per day (Company Report, 1969). MacKenzie (1968, p. 75) reported that the maximum grade was 2.58% Ni. The development shaft became an intake for fresh air in 1970. Production was reduced to 2800 tons per day in 1971, "...to counteract weak nickel markets and avoid inventory build-up", (Northern Miner, Aug. 2, 1973).
Amax Exploration, Inc. flew an airborne geophysical survey over the area in 1967 under Airborne Permit 66. A small coincident magnetic and electromagnetic anomaly was found in this vicinity.
As of December 31, 1969 proven ore reserves of Thompson, Birchtree and possibly Pipe and Soab were 71 472 000 tons with a nickel content of 1 336 000 tons and a copper content of 104 000 tons (INCO Prospectus for 1970).
As of December 31, 1970 proven ore reserves of Thompson, Birchtree and possibly Soab and Pipe were 71 550 000 tons with a nickel content of 1 400 000 tons and a copper content of 100 000 tons (INCO Prospectus for 1971). According to Canavest House Limited (December, 1971) this is equivalent to 1.95% Ni and 0.14% Cu. The reserves for Thompson (36 million tons) and Birchtree (14 million tons) were estimated to grade 2.30% Ni and 0.15% Cu.
Production in 1976 from Birchtree comprised 5900 tons per day operating at two shifts per day, five days a week. Grade was estimated at 2% Ni. Shaft deepening, another 2000 feet, was underway (Financial Post, June 19, 1976).
Due to market conditions, Birchtree production was suspended in December, 1977 (INCO Ann. Rept. 1977), but the mine was to be maintained on a standby basis (Northern Miner, October 27, 1977). Re-opening of Birchtree was considered in 1981, but was deferred in favour of development of the Thompson open pit mine (see: 63P/12 NI 2).
Production rate: 1969 4000 wet short tons per day
1973 2800 wet short tons per day

Production capacity: 4000 tons per day
Ore trucked to Thompson Mine for processing.
Total Production from Thompson and Birchtree

Year Tonnage % NI % CU
1969 3,198,000 2.25 0.15
1970 3,867,000 2.18 0.14

(INCO Prospectus for 1970, 1971)
Airborne Permit 66, NW 12, 63P; Non-confidential Assessment Files; Geoscience Data Section, Manitoba Mineral Resources Division.
Bell, C.K., 1965: Reconnaissance Mapping in Upper Nelson River Area in Report of Activities; Field, 1964; Geological Survey of Canada Paper 65-1, p. 94.
Bell, C.K., 1971: Boundary Geology, Upper Nelson River Area, Manitoba and Northwestern Ontario in Geoscience Studies in Manitoba; Geological Association of Canada, Special Paper 9, p. 11-40.
Brooks, R.H., and Myers, R.E., 1979: Blasthole Stoping at INCO's Birchtree Mine; C.I.M. Bull., v. 72 no. 806 (June, 1979), p. 68-71.
Coats, C.J.A., Quirke, T.T., Bell, C.K., Cranstone, D.A., and Campbell, F.H.A., 1972: Geology and Mineral Deposits of the Flin Flon, Lynn Lake and Thompson Areas, Manitoba, and the Churchill-Superior Front of the Western Precambrian Shield; International Geological Congress, 24th Session, p. 63-71.
Davies, J.F., 1960: Geology of the Thompson-Moak Lake District, Manitoba; C.I.M.M. Bull., v. 81, no. 4, p. 101-4.
Dawson, A.S., 1952: Geology of the Partridge Crop Lake Area; Manitoba Mines Branch, Publication 41-1.
Douglas, R.J.W. (Ed.), 1970: Geology and Economic Minerals of Canada; Geological Survey of Canada , Economic Report 1, p. 180, 1.
INCO Limited: NW 12, 63P, Corporate File, Manitoba Mineral Resources Division.
INCO Limited: Corporation File, Mineral Policy Sector, Ottawa.
International Nickel Company of Canada, Limited, The, 1965: Birchtree Mine in Manitoba; Western Miner, v. 38, no. 10, Oct., p. 106, 7.
Jip, Moe, Zip, NW 12, 63P; Non-confidential Assessment File; Geoscience Data Section, Manitoba Mineral Resources Division.
Kilburn, L.C., Wilson, H.D.B., Graham, A.R., Ogura, Y., Coats, C.J.A., and Scoates, R.F.J., 1969: Nickel Sulphide Ores Related to Ultrabasic Intrusions in Canada; Economic Geological Monograph 4, p. 276, 7.
Len, 8, 9, 14-16, NW 12, 63P; Non-confidential Assessment File; Geoscience Data Section, Manitoba Mineral Resources Division.
MacKenzie, B.W., 1968: Nickel-Canada and the World; Mineral Resources Division, Ottawa, Mineral Report 16, p. 69, 75.
Patterson, J.M., 1963: Geology of the Thompson-Moak Lake Area; Manitoba Mines Branch, Publication 60-4.
Paula, May, NW 12, 63P; Non-confidential Assessment File; Geoscience Data Section, Manitoba Mineral Resources Division.
Udo 3-11, NW 12, 63P; Non-confidential Assessment File; Geoscience Data Section, Manitoba Mineral Resources Division.
Wilson, H.D.B., and Brisbin, W.D., 1961: Regional Structure of the Thompson-Moak Lake Nickel Belt; C.M. & M. Trans., v. LXIV, 1961, p. XXX and Bull., v. 54, no. 595 (November, 1961), p. 815-23.
Map 63P/12W, Thompson (Topographic), Scale 1:50 000; Surveys & Mapping Branch, Ottawa.
Map 2601 G, Thompson (Aeromagnetic), Scale 1:63 360; Manitoba Mines Branch and Geological Survey of Canada.
Map 41-1, Partridge Crop Lake Area (Geology), Scale 1:126 720; accompanied Publication by Dawson (1952); Manitoba Mines Branch.
Map 51-3, Sipiwesk (Geology), Scale 1:253 440; accompanied Marginal Notes by Harrison (1951), Geological Survey of Canada.
Map of Moak-Setting Lake Area (Geology), Scale 1:96 000; accompanied Coats et. al. (1972), International Geological Congress.
Maps, SW 6, 63P (Claim), Scale 1:31 680; "Circa 1975", Claim Map Series, Mining Recording, Manitoba Mineral Resources Division.
Minor pyrrhotite and more rarely, chalcopyrite were found on several claims in NW 12, 63P:

Claim Name Assessment
U No. File Mineralization

Jip 129 Jip, Moe, Zip Very minor Pyrrhotite; highest assay .08% Ni.
(P 52458)

Len 10, Len Len 8, 9, 14- Minor Pyrrhotite, chalcopyrite; visual estimate 15% pyrrhotite
24. Frac. 16 1% chalcopyrite.
(P 9328C, 40C)

Paula Paula, May Minor pyrrhotite and chalcopyrite.
(P 56089)

Udo Udo 3-11 Pyrrhotite.
(P 24044)
Compiled/Revised by:
11-65 2-73 11-75 05-82