Ontario Mineral Inventory

Ontario Geological Survey
Permanent Link to this Record: MDI42A09SE00012

Record: MDI42A09SE00012

General

Commodities

Primary Commodities: Gold, Silver

Location

Township or Area: Munro

Latitude: 48° 33' 1.34"    Longitude: -80° 14' 48.32"

UTM Zone: 17    Easting: 555588.189   Northing: 5377748.72    UTM Datum: NAD83

Resident Geologist District: Kirkland Lake

NTS Grid: 42A09SE

Point Location Description: The shaft 1.40 km north and 2.10 km east of the southwest corner of Munro Township.

Location Method: Conversion from MDI

Access Description: The Croesus Mine is in southwest Munro Township, about 15 km east of Matheson. The old shaft and most of the underground workings are on patented claim no. 11581, the northeast quarter of the north half of lot 10, concession I, Munro Township and may be reached from Highway 101 via a 2 wheel drive vehicle passable dirt road (as indicated by Satterly 1952), although this road is often flooded and made impassable by beavers. The shaft area may also be reached from the north via a 2 wheel drive vehicle passable road which may be reached from Highway 101 via the Canadian Johns Manville Co. Ltd. Munro (asbestos) Mine open pit and surface facility area. The Croesus Mine property consisted in 1915 of contiguous patented claim nos. 11581, 4040, 4039, the northeast, northwest and southwest quarters of the north half of lot 10, concession I, respectively, and patented claim no. 2562, the northeast quarter of the south half of lot 10, concession I, Munro Township.

Exploration History

1914: Mr. Dobie and Mr. Leyson: spectacular Au discovered; stripping, pitting completed. 1915: Dominion Reduction Company: purchased Dobie-Leyson claim; mined property via inclined shaft; formed Croesus Gold Mines Ltd.; 100 tons ore milled yielding 3,534 oz Au, 427 oz Ag. 1916: Croesus Gold Mines Ltd.: drifting and x-cutting (863 ft) on 100, 150, 200, 250, 300, and 400 levels; 50 ton/day mill erected on property, some ore milled; shaft extended to 400 ft level; drifting and x-cutting (1,268 ft), raising (130 ft) on 150, 200, 250, 300, and 400 levels; 477 tons ore milled yielding 2,495 oz Au, 216 oz Ag: [1917]: drifting and x-cutting (700 ft) on 300 level; mine fire killed many workers; 1,541 tons of milled ore yielded 2,837 oz Au, 281 oz Ag: [1918]: rebuilt mill, replaced surface plant; 692 tons milled ore yielded 3,123.9 oz Au, 254.18 oz Ag; operations suspended until after WW I: [1923]: renewed mining; removed u/g pillars; 518 tons ore milled yielding 1,292 oz Au, 105 oz Ag. 1930: Munro Croesus Gold Mines Ltd.: purchases mine 1931: Munro Croesus: incorporated; milled 550 tons ore yielding 190.54 oz Au, 35 oz Ag on site: [1932]: 276.43 oz Au, 26 oz Ag recovered from dump material: [1934]: 205 tons of milled surface dump material yielded 298.54 oz Au, 24 oz Ag from 25 ton/day on site mill.: [1935]: 1,000 tons of ore and waste hoisted; 1,237 tons of milled material yielded 724.46 oz Au, 48 oz Ag; drifting and x-cutting (1,018 ft) completed from 1932-1935.: [1936]: optioned property to Tellaurum Gold Mines Ltd.; 82.827 oz Au, 7 oz Ag yielded fro 13 tons ore: [1937]: Tellaurum option lapsed: [1948]: 5 oz Au recovered. 1965-70: C. H. W. Cane: owned property. 1976: property held by private syndicate; trenching and diamond drilling completed. (see KL-4802) 1977: M. C. Group Management Ltd.: controlled property. [1978]: An exploration program of backhoe stripping and 5 diamond drill holes totalling 644.7 ft. [1981]: Tailings shipped to Pamour mill is 2 lots. 61.47 ounces of gold recovered from 1396.2 tons. 1987: Munro-Croesus Ltd.: acquires property.

Geology

Province: Superior

Subprovince: Abitibi

Terrane: Wawa-Abitibi

Belt: Abitibi

Tectonic Assemblage: Stoughton-Roquemaure

Geological Age: Mesoarchean  

Metamorphism Grade: Greenschist

Geology Comments

Dec 07, 2005 (R Degagne) - The mine area is between two regional scale (locally) southeast striking structures: the Contact Fault and the Munro Fault Zone. The Contact Fault is about 1,200 southwest of the shaft and is developed at the contact between distal turbidite facies clastic (and, rarely, chemical) (meta)sediments of the (Archean) Porcupine Group (which strike southeast, dip steeply and face north) to the south and subaqueously deposited (meta)volcanic rocks of the Stoughton-Roquemaure Group to the north. Along strike to the northwest in Beatty Township, the Contact Fault is a north dipping normal fault which crosscuts up-section strata and may have developed along it discontinuous zones of carbonatization and sericitization (Johnstone 1987). The Contact Fault is also a locus of intrusive activity in Beatty Township, with small feldspar phyric felsic and peridotitic bodies intruded along it. In southwest Munro Township, the Contact Fault is marked by locally developed carbonatization and sericitization. Johnstone (1987) presents evidence which suggest that motion along the Contact Fault was largely steeply oblique slip (rather than strike slip) and that north block up relative motion is consistent with observations made by him elsewhere in the area. The Munro Fault Zone is about 600 northeast of the mine area and underlies a wide (locally, about 600 m across) swamp. It has been mapped (Johnstone 1987) of a zone of parallel, southeast striking and subvertically dipping shears which are confined to a conformable ultramafic horizon.

Lithology

Lithology Comments

Dec 07, 2005 (R Degagne) - The area is underlain mainly by variably glacial drift covered massive, pillowed, flow brecciated, and hyaloclastic basalt which strikes 070, dips steeply, faces north, and occupies part of the south limb of the southeast striking and northwest plunging McCool Hill Syncline, the axis of which is about 6.4 km northeast of the mine (Satterly 1952, Johnstone and Trowell 1985, Johnstone 1987; Vagners 1984; McClenaghan et al. 1988, 1987; Steele 1988). Geochemical analysis of basalt in the indicates (Johnstone 1987) that the volcanic rocks here are tholeiitic. Several northeast to east northeast striking crossfaults across which limited apparent horizontal offset has taken place occur in the mine area. Rocks intruding the supracrustal bedrock succession include narrow (metres in width) lamprophyre dikes and green/grey quartz porphyry dikes (Satterly 1952, assessment files). A north striking narrow (tens of metres in width) diabase dike of the (Proterozoic) Matachewan swarm (Heaman 1989) occurs about 330 m east of the shaft. Country rocks hosting the main vein include unsheared basalt(to the northeast where the vein is nonauriferous) and an apparently variable assemblage of foliated and complexly folded (assessment files) sulfidic (interfragment pyrrhotite, pyrite, and possibly chalcopyrite and arsenopyrite bearing) and carbonatized flow breccia, chert and discontinuously developed carbonaceous tuff (where the vein contained spectacular coarse grained visible gold). Stripping east of the shaft exposes sulfidic flow breccia, but descriptions of rocks hosting the vein (assessment files) indicate that at depth, a carbonaceous and slatey tuffaceous interflow facies is present.

Mineralization

Mineralization Comments

Dec 07, 2005 (R Degagne) - Most descriptions of Croesus mineralization indicate that the mineralized shoot containing spectacular free gold was confined to exclusively that part of the Croesus Vein which was hosted by the sulfidic flow breccia and/or interflow material. Some accounts indicate that anomalous gold values occurred in the basalt marginal to the vein and in (vein marginal?) sulfide minerals (The Northern Miner, May 20, 1916; April 28, 1917). The dark yellow colored coarse native gold is described to have cemented highly fractured glassy blue/grey quartz vein material. To the northeast (presumably where the vein was hosted by basalt) the Croesus Vein was described to be a pearly white color and was not fractured (assessment files). Sulfide minerals associated with the high grade shoot included arsenopyrite (closely associated with the gold in the vein as seams within the quartz and as massive clots, nodules and disseminations of fine grained acicular crystals within the sulfidic host breccia and/or tuff), and rare pyrite and sphalerite. Descriptions of the arsenopyrite mineralization differ. Information in the assessment files indicates that in the footwall (and by implication, not the hanging wall?) of the ore shoot, the rock was highly silicified and heavily mineralized with pyrite and arsenopyrite. Lovell and Ploeger (1977) reported that both the immediate hanging wall and footwall contain fine grained acicular arsenopyrite. The assessment files also indicate that anomalous amounts of gold (as much as 0.50 ounce of gold per ton) may be associated with wall rock heavily mineralized with arsenopyrite whereas pyritic wall rock is only weakly anomalously auriferous. A silver colored telluride mineral (querried to be sylvanite) was also observed (assessment files), in the Croesus Vein. Silicate minerals associated with the gold mineralization include tourmaline (occurring within the Croesus Vein), garnet , and carbonate and sericite in wall rocks.

Alteration Comments

Dec 07, 2005 (R Degagne) - Silicate minerals associated with the gold mineralization include tourmaline (occurring within the Croesus Vein), garnet (marginal to the Croesus Vein where it is hosted by basalt) (assessment files) and carbonate and sericite in wall rocks adjacent to the vein (Whittaker 1985). The Contact Fault is also a locus of intrusive activity in Beatty Township, with small feldspar phyric felsic and peridotitic bodies intruded along it. In southwest Munro Township, the Contact Fault is marked by locally developed carbonatization and sericitization.

Mineral Record Details

Mineral Zones - Size and Shape

Rank: 1       Structure Type: Fold

Rank: 1       Structure Type: Fold

Site Visit Information

Date: Jan 31, 1997

Geologist: R Degagne

Notes: Although additional high grade low tonnage deposits such as the Croesus will be difficult to locate, proximal carbonate alteration and the presence of anomalous concentrations of arsenic (in arsenopyrite) may prove helpful in locating this deposit type. Subcropping deposits might be expected to produce glacial dispersion fans characterized by anomalous amounts of free gold, arsenopyrite (and arsenic), telluride minerals (and tellurium), tourmaline, and garnet.

References

File - Resident Geologist file KL-4802

Publication Number: Date:

Author:

Publisher Name:

Location: Kirkland Lake RGP office

Map - Quaternary geology of Matheson area, Cochrane District

Publication Number: P2735 Scale: 1:50,000    Date: 1985

Author: Vagners U.J.

Publisher Name: Ontario Geological Survey

Location:

Map - Township of Munro, District of Cochrane, Ontario

Publication Number: M1951-05 Date: 1997

Author: Satterly J., Hogg N.

Publisher Name: Ontario Dept. of Mines

Location:

Part - Abitibi-Night Hawk gold area, District of Timiskaming

Publication Number: ARV28-02.001 Page: 55-56  Date: 1998

Author: Knight C.W., Burrows A.G., Hopkins P.E., Parsons A.L.

Publisher Name: Ontario Bureau of Mines

Location:

Map - Geophysical/geochemical series, Matheson-Black River area, Munro Township, airborne electromagnetic survey, total intensity magnetic survey, District of Cochrane

Publication Number: M80586 Scale: 1:20,000    Date: 1984

Author: Questor Surveys Ltd.

Publisher Name: Ontario Geological Survey

Location:

Part - Geology of Munro Township

Publication Number: ARV60-08 Page: 48-51  Date: 1997

Author: Satterly J.

Publisher Name: Ontario Dept. of Mines

Location:

Map - Black River-Matheson Area

Publication Number: OFM0013 Scale: 1:15,840    Date: 1985

Author: Johnstone R.M., Trowell N.F.

Publisher Name:

Location:

Mono - Gold deposits of Ontario, part 1, districts of Algoma, Cochrane, Kenora, Rainy River, and Thunder Bay

Publication Number: MDC013 Date: 1971

Author: Ferguson S.A., Groen H.A., Haynes R.

Publisher Name: Ontario Dept. of Mines and Northern Affairs

Location:

Map - Geological series, Precambrian geology of the Magusi River area, Cochrane and Timiskaming districts

Publication Number: P2434 Scale: 1:63,360    Date: 1982

Author: Jensen L.S.

Publisher Name: Ontario Geological Survey

Location:

Map - Geological series, Precambrian geology of the Magusi River area, Cochrane and Timiskaming districts

Publication Number: P2434 Scale: 1:63,360    Date: 1982

Author: Jensen L.S.

Publisher Name: Ontario Geological Survey

Location:

Mono - Preliminary report on the Timmins-Kirkland Lake area, gold deposits file

Publication Number: OFR5467 Page: G0005  Date: 1983

Author: Hodgson C.J.

Publisher Name: Ontario Geological Survey

Location:

Folio - Munro Township, District of Cochrane

Publication Number: GDIF361 Date: 1997

Author: Kirkland Lake RGO

Publisher Name: Ontario Geological Survey

Location:

Map - Beatty-Munro gold area, District of Timiskaming

Publication Number: ARM24A Scale: 1:63,360    Date: 1998

Author: Hopkins P.E., Greenland C.W.

Publisher Name: Ontario Bureau of Mines

Location:

Mono - Mineral occurrences, deposits, and mines of the Black River-Matheson area

Publication Number: OFR5735 Page: 278-292  Date: 1990

Author: Bath A.C.

Publisher Name: Ontario Geological Survey

Location:

File - Res/Reg Property Visit KL #154

Publication Number: PV-154 Date: 1978

Author:

Publisher Name:

Location: Kirkland Lake RGP office

Article - 1976 report of the Kirkland Lake Resident Geologist

Publication Number: MP071.006 Page: 81-94  Date: 1997

Author: Lovell H.L., Ploeger F.R.

Publisher Name: Ontario Geological Survey

Location:

Book - Stop 15: Stratigraphy & Structure in the Vicinity of the Croesus Gold Mine, Munro Township; GAC Field Trip Guidebook, Toronto

Publication Number: GAC FT Date: 1978

Author: MacVeigh, J. G.

Publisher Name: Geological Association of Canada

Location: FIELD TRIP GUIDEBOOK, GAC, TORONTO

Article - Precambrian geology of the Black River-Matheson (BRIM) area, District of Cochrane

Publication Number: MP126.056S Date: 1997

Author: Johnstone R.M., Trowell N.F.

Publisher Name: Ontario Geological Survey

Location:

Book - Geology and petrogenesis of the Archean Abitibi belt in the Kirkland Lake area, Ontario

Publication Number: MP123 Date: 1985

Author: Jensen L.S., Langford F.F.

Publisher Name: Ontario Geological Survey

Location:

Part - The Beatty-Munro gold area

Publication Number: ARV24-01.004 Date: 1998

Author: Hopkins P.E.

Publisher Name: Ontario Bureau of Mines

Location:

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