MINERAL INVENTORY FILE NO.
999
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PRODUCT
PLATINUM
NTS AREA
52L6NW
REF.
PT 1
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NAME OF PROPERTY
DUMBARTON MINE LEASE
(Dumbarton Mines, Maskwa West Pit)
OWNER OF OPERATOR ADDRESS
1988 – Maskwa Nickel Chrome Mines Limited (N.P.L)
Box 40, Commerce Court West
Toronto ON M5L 1B4
OBJECT LOCATED
Centre of Dunbarton M.C.
MINING DIVISION
Winnipeg
Latitude
5028.15’
Longitude
9526.74’
Uncertainty (m)
500 m
UTM Zone
_____
Easting
_______
Northing
_______
L.S./Quarter Section
___
Section
26, 35
Township
17
Range
15 EPM
DESCRIPTION OF DEPOSIT
The occurrence is on the south limb of the Bird River Sill.
In a company report of Stanmore Mining and Smelting Limited, Browne (1938) reported that "traces of platinum group, gold, and silver were found in most of the Oiseau cores". The company's 'Oiseau property' appears to be within the 'Dumbarton Mine lease' area (see Remarks).
In 1968, Consolidated Canadian Faraday Limited did 1219 m (4000 ft) of drilling on the Dumbarton Mine property: platinum and palladium values were reported to be "interesting" (Mineral Inventory card 52L/6 NI 1). Later, two random samples of flotation concentrate indicated metal contents (by weight) of: 4.69% Cu, 8.50% Ni, 1.234 g/tonne (0.036 oz/ton) Pt, 3.771 g/tonne (0.11 oz/ton) Pd; and 5.96% Cu, 9.88 % Ni, 1.097 g/tonne (0.032 oz/ton) Pt, 4.114 g/tonne (0.12 oz/ton) Pd (Karup-Moller and Brummer, 1971). Small amounts of PGM by-products were produced from the deposit (see History of Production).
In 1986, old drill-core from the Dumbarton Mine and Maskwa West pit areas was sampled by the Manitoba Mines Branch; drill-core assays of up to 220 ppb Pt, 320 ppb Pd over 0.3 m (1 ft) intervals were reported. Results are shown in Table 1.
The Geological Survey of Canada (GSC) reported contents of up to 260 ppb Pt and 1760 ppb Pd in Ni-Cu ores from the Dumbarton Mine, which were analyzed using a lead fire assay and carbon-rod atomic absorption spectrometry method. The ore samples were obtained from ore collections of the GSC. Results, representing heavy mineral concentrates, are shown in Table 2.
Geological descriptions of these areas are detailed in Mineral Inventory cards 52L/6 NI 1, NI 2.
ASSOCIATED MINERALS OR PRODUCTS OF VALUE
Copper, nickel, arsenic, gold, silver, cobalt, lead, chromite, zinc.
HISTORY OF EXPLORATION AND DEVELOPMENT
Table 1: Pt and Pd in ore of the Dumbarton Mine and the Maskwa West Pit
(Source: Theyer, 1986:126)


DDH#................…Sample # From-To… Pt………...Pd……………..Mineralization
FB 74/42 DM-1.....204'-205'………….......30………....64………………..3-5% py, minor cpy
FB 74/42 DM-2.....209'-210'…………........LT 20……..63………………..2-3% py
FB 74/42 DM-3..…225'-226'…………....... LT 20……..16………………..1% py and cpy
FB 74/42 DM-4..…229'-230'…………....... 20…….......66……………….2-4% py and cpy
FB 74/42 DM-5..…233'-234'…………....... 40………....61……………….2-3% py and po intergrown
FB 74/42 DM-6..…241'-242'…………....... 30………....75……………….5% py in clusters
FB 74/42 DM-7..…296'-297'…………....... 30………....320…..……......7-8% py, minor po and cpy
FB 74/43 DM-9..…307'-308'…………....... 50………....210……………..3-5% diss. py minor cpy
FB 74/43 DM-10 …319'-320'…………....... 60………....280………….…1-2% diss. py
FB 74/43 DM-11 …359'-360'…………....... 50………....200…………….1% diss. py

B45…..DM-12… …321'-322'…………..LT 20…….........7……………….1% diss. py
B45…..DM-13… …335'-336'…………......30……….....210………………10-15% py and po
B45…..DM-14… …367'-368'…………...LT 20…….......43……………….20-25% py and po

B48…..DM-15....…318'-319'…………..LT 20…….........2……………….sporadic diss. py
B48…..DM-16… …322'-323'…………...LT 20……........26……………….10% diss. py
B48…..DM-17… …352'-353'………….....220……........190……………….10% py in clusters and veins
............….........and 357'-358'……..

B50…..DM-18… …394'-395'…………....... 30……….....32……………….approx. 80% po

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LT - less than


Table 2: Preliminary analyses of Ni-Cu ores from the Dumbarton Mine
(Source: Jonasson et al., 1987)

..................................................Pt.....Pd....Au.......Pt
....................As....Sb....Mo...Hg...ppb...ppb...ppb...Pt+Pd...Se...Te...Bi...U.......Sample

Dumbarton....11......1.....5.....0.10..260...625...35...0.294.....36....8.....3...0.00....467
Mine, .............1......1....5.....0.21..255..1760...80...0.127.....63....9.....3...0.00....468
Manitoba.........3......1...5......0.16..90....1280...25...0.066......-.....0.....3...0.05....469
......................3......1...5......0.08...0......500...40...0...........33....0.....3...0.08....470
......................1......1...3......0.06...0.....465...25....0...........48....0.....3...0.00....537
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Mean Values ..1......1..3.....0.12..121...926....41....0.116....45....3.....-.... -
D.L.................1......1..3.....0.01...5......5........5.................1.....1.....3....0.005
- indicates no data; D.L. = detection limits; values in ppm unless noted.

The Dumbarton Mine is located about 4.8 km west of Oiseau (Bird) Lake, 5.6 km north of Bernic Lake and is crossed over by Provincial Highway No. 315; the Maskwa West nickel deposit is 1.2 km southwest of the Dumbarton Mine.
The Dumbarton deposit was mined from 1969 to 1973 by Dumbarton Mines Limited, a company jointly owned by Consolidated Canadian Faraday Limited and Maskwa Nickel Chrome Mines Limited (59% owned by Falconbridge Nickel Mines Limited); the Maskwa West Open Pit was mined in 1975-76 by Dumbarton Mines Limited.
A detailed history of mining exploration and development in this area can be found in Mineral Inventory cards 52L/6 NI 1, NI 2, CU 2.
HISTORY OF PRODUCTION
Table 3: Dumbarton Mine PGM production; 1970 - 1973

1970.....18 662 g (600 oz) PGM*
197l......24 882 g (800 oz) PGM*
1972.....24 882 g (800 oz) PGM*
1973 (?) 9 700 g (311.97 oz) Palladium**

*Report of the Task Force, 1974.
**Consolidated Canadian Faraday Limited, Annual Report 1973.

Table 4:Dumbarton Mines Limited- Estimated Metal Production for Manitoba (Source: Report of the Task Force on Manitoba Minerals Policy, 1974: 90).


Year.........................Metals (thousands)

.........................Cobalt......Copper.....Gold......Nickel.....Platinums*...Silver
...........................(lbs)........(lbs)........(oz)......(lbs)...........(oz)...........(oz)
1970...................14.2.........1 369.......0.5.......3 048.........0.6............9.4
1971...................12.4.........1 564.......0.4.......3 711.........0.8............9.8
1972...................16.1.........1 493.......0.5.......4 032.........0.8...........10.4
*Calculated using Pt/Ni: 0.0004 for 1970; and Pt/Ni: 0.0002 for 1971 and 1972
REFERENCES
Browne, L.M.
1938: Information on Maskwa and Oiseau property of Stanmore Mining and Smelting Limited; in Manitoba Mines Branch, Unpublished Information File, 52L/12NE.
Canadian Minerals Yearbook
1974: Platinum metals; Energy, Mines and Resources, Mineral Report No. 24, p.393.
Coats, C.J.A., Stockford, H.R. and Buchan, R.
1979: Geology of the Maskwa West nickel deposit, Manitoba; The Canadian Mineralogist, v. 17, p.309-318.
Davies, J.F.
1955: Geology and mineral deposits of the Bird Lake area, Lac du Bonnet Mining Division, Manitoba; Province of Manitoba, Department of Mines and Natural Resources, Mines Branch, Publication 54-1, 44p.
Fogwill, D.W. and Bamburak, J.D.
1987: Mining in Manitoba; Manitoba Energy and Mines, Mineral Education Series, p.25.
Jonasson, I.R., Eckstrand, O.R. and Watkinson, D.H.
1987: Preliminary investigations of the abundance of platinum, palladium and gold in some samples of Canadian copper-nickel ores; in Current Research Part A; Geological Survey of Canada, Paper 87-1A, p.835-839.
Karup-Moller, S. and Brummer, J.J.
1971: Geology and sulphide deposits of the Bird River claim group, southeastern Manitoba; in Geoscience Studies in Manitoba, ed. A.C. Turnock; Geological Association of Canada, Special Paper No. 9, p.143-154.
Manitoba Mines Branch:
a Corporation Files; Consolidated Canadian Faraday Limited; Dumbarton Mines Limited.
b Mineral Inventory cards; 52L/6: NI 1 (Dumbarton Mine), NI 2 (Maskwa West), CU 2 (Colossus); 52L/5: PT 1 (Chrome), PT 2 (Trimpus).
c Annual Reports; 10th p.69, 11th p.114-115.
d Unpublished Information Files; 52L/6, 52L/12NE.
Report of the Task Force on Manitoba Minerals Policy, 1974; Department of
Mines, Resources and Environmental Management, p. 54, 90, 115, 117-119.
Theyer, P.
1980: Stratigraphic setting of selected ultramafic bodies in the Superior and Churchill provinces and certain aspects of nickel-copper deposits in the Thompson Nickel Belt; Manitoba Department of Energy and Mines, Mineral Resources Division, Economic Geology Report ER79-2, p.21
MAP REFERENCES
*Map 52L/6, West, Ryerson Lake (Topo), Scale 1:50 000, Mines and Technical Surveys, Canada.
Map 1194G, Ryerson Lake, (Aeromag), Scale 1:63 360, Manitoba Mines Branch and Geological Survey of Canada.
Map 54-1, Bird Lake area, (Geol), Scale 1:12 000 - Accompanying Report by Davies (1955), Manitoba Mines Branch.
Preliminary Map 1972F-1, Geological compilation map of the Bird River area, (Geol), Scale 1:50 000, by D.L. Trueman, Manitoba Mines Branch.
Preliminary Map 1975F-9, Bird River area east (Geol), Scale 1:31 680, by D.L. Trueman, Manitoba Mines Branch.
Map ER79-2-6, Geology and mineral deposits of the Bird River Sill (Geol), Scale 1:125 000 - Accompanying Report by Theyer (1980), Manitoba Mineral Resources Division.
#Claim Map Series NW 6, 52L, Scale 1:31 680, circa 1974, Mining Recording, Manitoba Mines Branch.
REMARKS
1. Stanmore Mining and Smelting Limited's 'Oiseau property' consisted of 53 claims in the Bird (Oiseau) River area, many of which are found within the 'Dumbarton Mine lease' area (see Mineral Inventory card 52L/6 NI 1). Stanmore had apparently incorporated in 1937 to take over the holdings of Great Falls Mining and Smelting Company, Limited and Northfield Mining Company, Limited.
It was reported that 1737 m (5700 ft) of diamond-drilling was done on the Dumbarton, Chance, Martin, Colossus M.C., Colossus #12, #13, and #15 claims in 1936, with 184 m (605 ft) on the Colossus claim (see 52L/6 CU 2) in 1937.
2. Other platinum occurrences on the south limb of the Bird River Sill are documented in Mineral Inventory cards 52L/5 PT 1, PT 2.
URL
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REMARKS
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NOTES
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Compiled/Revised by:
PA
Date
2-88 19__-__-__ 20__-__-__