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Snow Lake District - Chisel, Stall, Osborne, Anderson Lake, Lalor, New Britannia, Reed, Spruce Point |
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Manitoba, Canada |
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Zn Cu Au Ag
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Super Porphyry Cu and Au
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IOCG Deposits - 70 papers
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The Chisel Lake, Stall Lake/Rod, Lalor, Reed, Osborne Lake, Anderson Lake, Dickstone and associated cluster of volcanic hosted massive sulphide (VHMS) copper-zinc-gold deposits, as well as gold-bearing volcanic hosted quartz-carbonate veins such as Britannia, are located in northern Manitoba, in Canada, ~550 km NNW of Winnipeg, and 525 km NE of Saskatoon. The main cluster of deposits in the Snow Lake district and are situated within a 40 km radius around the town of Flin Flon. The key deposits include Chisel Lake, Chisel North, Chisel Open-pit, Lalor, Stall Lake, Osborne Lake, Anderson Lake, Spruce Point and Dickstone all of which contained >1 Mt of economic ore, as well as the smaller satellite deposits that included Rod, Ghost, Photo Lake and Lost.
Geological Setting
The regional and district scale setting and context of this group of deposits is described in the separate Flin Flon-Glennie Complex VHMS Deposits record.
The Anderson Lake, Chisel Lake and Snow Lake sequences of the Snow Lake district are described in the Flin Flon-Glennie Complex VHMS Deposits - Overview record.
Chisel Lake, Chisel North and Ghost Lake Deposits (#Location: 54° 49' 45"N, 100° 7' 17"W)
The Chisel Lake orebody was discovered in 1956 when a 3.5 Mt Zn sulphide orebody was outlined and the first ore shipped to Flin Flon in September 1960, and the ore reserves were stated with 3.471 Mt @ 11.6% Zn, 51 g/t Ag, 22 g/t Au, 0.52% Cu, 0.7% Pb. The mine closed in March 1994, due to depletion of resources.
The deposit occurs in metasedimentary and volcanic rocks of the Palaeoproterozoic Amisk Group. In the immediate Chisel Lake area, the sequence comprises, from the base (Williams, 1966):
• Pillowed or amygdaloidal basalt - fine- to medium-grained black amphibolites, generally with a lineation produced by the alignment of prismatic amphibole crystals, and are composed of amphibole, plagioclase, biotite, quartz, epidote, garnet, and calcite;
• Massive flow rocks - a grey rock, which is lighter coloured more siliceous than the basalts, with a composition approaching andesite. It has a crystalloblastic texture and is composed of quartz, amphibole. plagioclase, quartz, biotite, epidote, calcite, garnet and magnetite;
• Basic pyroclastic rocks, with minor acidic to intermediate pyroclastic rocks - composed of agglomerates, tuffs, and finer ash deposits. The agglomerates contain clasts that are generally <25 cm in diameter, although, local fragments or amygdaloidal bombs may be up to 1 m across. The clastic material is poorly sorted, and bedding is not conspicuous. Clasts are of dark amphibolite and rounded bombs of amygdaloidal lava, with white-weathering siliceous volcanic fragments dominant in places. The matrix is fine- to medium-grained, dark green to black amphibolite;
• Amphibolite - highly deformed, and in places, strongly garnetiferous rocks, considered to be largely derived from mafic pyroclastic material;
• Metasedimentary rocks - staurolite-garnet schists - these are rare, and where present comprise coarsely crystalline staurolite-garnet-biotite schists, with lesser quartz, plagioclase (oligoclase), chlorite and muscovite, with accessory magnetite, apatite, zircon and sulphides;
• Quartz-eye gneiss - these are of uncertain origin, but may represent metamorphosed crystal tuffs. It has a porphyritic texture and is mainly composed of quartz and sodic plagioclase, generally oligoclase (together accounting for 80% of the rock), with biotite and hornblende, minor potash feldspar, epidote, muscovite and garnet, and accessory apatite, pyrite, pyrrhotite, sphene, leucoxene and zircon;
• Quartzo-feldspathic rocks - which locally exhibit relict textures typical of pyroclastic rocks, although in most exposures metamorphic features have obscured original textures. They are fine- to medium-grained with a granoblastic texture, with a similar composition to the quartz-eye gneiss, made up of quartz and sodic plagioclase with lesser amounts of amphibole, biotite, garnet, epidote, potash feldspar and chlorite, but more mafic minerals than in quartz-eye gneiss.
• Intrusives - Shallow intermediate to basic rocks post date this sequence, as do younger still masses of metaperidotite, metagabbro and metadiorite. The tear shaped 1.8 x 9.8 km Chisel Lake intrusion, which bulges to the south, is a layered complex composed of these intrusive phases.
The sulphides of the main ore zone are accompanied by a considerable quantity of gangue vein material, mainly actinolite, tremolite, dolomite and chlorite. The rocks adjacent to the ore zone in both the footwall and hanging wall are metasedimentary protoliths, altered to garnetiferous biotite schists, with an assemblage of secondary quartz, sodic plagioclase, chlorite, staurolite, sericite, kyanite and andalusite, accessory carbonate, epidote, apatite and gahnite, and disseminations and veins of sulphide accompanied by silicification. The most conspicuous alteration is the development of sericite along shear surfaces and an apparent introduction of silica. Outward from the ore zone, in the hanging wall these rocks pass into garnetiferous amphibolites that are lithologically similar to massive flow rocks described above.
The orebody is made up of a series of nearly massive sulphide lenses, which occur along a structural discontinuity, striking northwest, running from Lost Lake to Chisel Lake, and extending beneath the latter. The orebody is also approximately coincident with the axial plane of a northwesterly plunging overturned syncline to the southeast of Chisel Lakeand strikes parallel to secondary structures in the layered rocks. The axial plane of this small fold strikes at ~90° to the NE-SW trending axis of the regional Threehouse synform, the main structure in the district (Williams, 1966), producing an interference structure known as the Chisel basin (Gagné et al., 2006).
The mineralised zone is somewhat irregularly, striking SE-NW, dipping at ~45°NE, while the SE end of the orebody rakes steeply towards the NW. The main ore lenses are each ~300 to 350 m long. The ore zone and country rocks are truncated by basic intrusive rocks of the Chisel Lake intrusion to the northwest.
The principal sulphides in the Chisel Lake orebody, in order of decreasing abundance, are: sphalerite, pyrite, pyrrhotite, chalcopyrite, galena and arsenopyrite, with lesser gudmundite, marcasite, meneghinite, tetrahedrite, a bournonite-seligmannite solid solution and native gold (Bence and Coleman, 1963). Most of the ores are medium to coarse grained and massive, with a granular texture, produced by an even distribution of subhedral to euhedral pyrite crystals surrounded by a matrix of sphalerite or other sulphide minerals. The sphalerite is dark brown to black and occurs with other sulphides in a groundmass dotted with pyrite crystals. Galena and tetrahedrite occur as blebs in massive sphalerite. Silver is present microscopically in tetrahedrite. Veins and disseminations of sulphides in the wall-rocks are preferentially associated with biotite and sericite (Phillips, 1979). Shearing and granulation appear to have continued during much of the period of ore deposition. Gangue material in the mineralised zone is strongly sheared, and pyrite crystals are commonly brecciated and broken. Similarly, later minerals in the paragenetic sequence, such as galena, display cleavage traces that are curved or broken, suggesting a deposition in a stress environment.
Gangue minerals within the ore zone, in decreasing order of abundance, are actinolite, dolomite, tremolite, chlorite, biotite, quartz, muscovite and talc, with minor gahnite, apatite, tourmaline, epidote, sphene and serpentine. Sulphides are found interstitial to silicate minerals of the gangue, but in places appear to replace the silicates and dolomite. Massive green gangue development within and adjacent to ore, composed mainly of coarse actinolite, in places, grade into granular dolomite-tremolite rocks. Galena occurs both in angular interstice between actinolite crystals, but also as streaks and bands parallel to cleavage, suggesting replacement. Similar textural relations are displayed between sphalerite and chlorite.
The Chisel North deposit was discovered in 1987 by deep drilling 1.5 km north of the original Chisel Lake deposit. It is located at the same stratigraphic position as the main Chisel mine orebody, but 300 m down plunge. The nearby Ghost Lake and Lost Lake deposits also occur along the same stratigraphic horizon.
Chisel North comprises a series of shallowly NE-dipping massive sulphide lenses that are located along the same stratigraphic horizon as the adjacent Chisel Lake deposit. Chisel North is interpreted to be a down-plunge extension of the Chisel Lake deposit (Galley et al., 1993). It is composed of four stacked lenses, whose long axes plunge subparallel to the regional stretching lineation and the axis of the Threehouse synform. These lenses are stacked in an en echelon fashion down the dip of the stratigraphy. The ore at Chisel North typically comprises lenses that are up to 20 m thick of silicate-dolomite-rich, semi-massive sphalerite rich ore with thin, massive sphalerite-pyrite or sphalerite bands containing up to 100% sulphide minerals. Pyrite is typically more abundant near the base of the ore horizon and locally massive pyrrhotite occurs near the hanging wall. The tabular ore lenses are locally underlain by discordant zones of disseminated and vein sulphides, mostly chalcopyrite and pyrrhotite. The hanging wall, throughout the deposit, is locally variably enriched in Au, Ag and Pb, with values of as much as 7 to 10 g/t Au, 300 g/t Ag and 1% Pb over a intervals of a few metres. However, this hanging wall mineralisation, is not homogeneously distributed and is usually found in association with tectonically remobilised sulphide veins, e.g., in the hanging wall of lens 4, mineralisation is associated with both late sulphide veins and disseminated arsenopyrite in the altered wallrock. The hanging wall lithologies consists of mafic volcanic wacke in the southern third of the Chisel North deposit, whilst the rest of the orebody is overlain by a heterolithic breccia, locally truncated by a fine-grained dioritic intrusion (Galley et al., 1993). In the vicinity of lens 4, the hanging wall is mostly occupied by the dioritic sill. The footwall to the Chisel North sulphide lenses is generally comprises recrystallised and hydrothermally altered quartz-feldspar phyric Chisel rhyolite and its volcaniclastic equivalents, altered to sericite and chlorite commonly with kyanite, biotite, staurolite and garnet porphyroblasts (Galley et al., 1993), hosting sericite- and chlorite-rich lenses containing Zn, Fe, Pb, Cu, As, Au and Ag (Gagné et al., 2006).
The Chisel North orebody, as well as the past producing Chisel, Photo Lake, Ghost Lake and Lost Lake mines, lie within the northwest-trending synclinal fold interference structure locally known as the Chisel basin, an ~5 km thick arc assemblage comprising mainly mafic wacke, mafic breccia, pillowed basalt and synvolcanic gabbro intrusions.
Both the mineralisation and host rocks are well foliated and isoclinal folds are pervasive. Sulphide mineralisation exhibits penetrative deformation structures and local redistribution of constituent mineral phases. Fabric elements and overprinting relationships developed in the orebody are the products of four discrete periods of ductile deformation. Although primary layering is locally preserved, outlining F1 folds, rocks in the mine generally have structural fabrics consistent with transposition of the orebody and host rocks and a composite S1-S2 transposition foliation is ubiquitous. The intensity of the early folding events in particular produced significant redistribution of the ore and fold thickening of mineralisation (Gagné et al., 2006; 2007).
The Ghost Lake deposit is located 900 m east of the Chisel Lake shaft. The host suite has been mapped as mafic pyroclastic rocks, amphibolites and quartz-feldspathic rocks. The orebody occurs within quartz-biotite-(garnet) gneiss, associated with chlorite-biotite schist, hornblende schist and carbonate rocks. Sericite is abundant in the mineralised zone. The hanging wall rocks are reported to be andesites, typical of the Amisk pyroclastic rocks, and older shallow intrusives (amphibolite). Footwall rocks contain staurolite. The ore occurs as irregular, solid sulphide lenses in an orebody similar in shape to that at Chisel Lake, that strikes NW and dips to the NE. The ore consists mainly of sphalerite, along with lesser chalcopyrite, pyrrhotite, pyrite and galena (Manitoba Science, Technology, Energy and Mine website; Phillips, 1979).
The Chisel Lake description is largely drawn from "Williams, H., 1966 - Geology and mineral deposits of the Chisel Lake map-area, Manitoba"; Geological Survey of Canada, Department Of Mines and Technical Surveys, Canada, Memoir 342
Dickstone Deposit (#Location: 4° 51'' 18"N, 100° 29' 24"W)
The Dickstone Mine was located 32 km west of the town of Snow Lake, and 25 km west of the Chisel Lake deposit, hosted within rocks of the Snow Lake assemblage, as described in the separate Flin Flon-Glennie VHMS deposits record. Production was commenced in 1970 and ceased in 1975 after being mined to a depth of 350 m.
The ore occurs in two elongate orebodies, hosted in a soft, fissile, dark green schist which lies within a heavily sheared zone that cuts fine-grained silicified andesite of the Amisk group. Massive diorite intruded the andesite ~30 m west of the ore-zone. The rocks overlying the deposit to the east are typical greenstones.
The two ore lenses are separated by ~425 m at surface. The larger No. 1 lens averages 3 m in thickness and has a strike length of ~225 m at surface, tapering downwards to 160 m at a depth of 100 m, although it continued to a depth of >300 m.
The main orebody comprises relatively coarse-grained, massive sulphides, mainly pyrrhotite, with lesser chalcopyrite, a considerable concentration of magnetite and minor amounts of pyrite, sphalerite and telluro-bismuthite. Much of the chalcopyrite is pitted and contains blebs of sphalerite. Magnetite forms large rounded grains with good cleavage.
Lalor Deposit (#Location: 54° 52' 00"N, 100° 08' 00"W)
The Lalor deposit is similar to other massive sulphide bodies in the Chisel sequence, namely Chisel Lake, Ghost Lake, Chisel North and Photo Lake, and is hosted within the same stratigraphic unit as the Chisel Lake and Chisel North deposits, 10 km to the south. The Chisel sequence is lithologically diverse and displays rapid lateral facies variations and abundant volcaniclastic rocks. It typically contains thin and discontinuous volcaniclastic deposits and intermediate to felsic flow-dome complexes. Both mafic and felsic flows have 'evolved' geochemical characteristics (relative to the underlying, 'un-evolved' Anderson sequence) consistent. These rocks have been subjected to lower to middle almandine-amphibolite facies metamorphism.
The footwall rocks have undergone extensive hydrothermal alteration and metamorphic recrystallisation, to produce somewhat exotic aluminous mineral assemblages including chlorite dominant schists, sericite dominant schists, and cordierite+anthophyllite gneisses. Other minerals indicative of hydrothermal alteration that occur extensively throughout these rather simplified rock assemblages include quartz, feldspar, kyanite, biotite, garnet, staurolite, hornblende and carbonate. Clinopyroxene, gahnite and anhydrite also occur locally. These assemblages are typical of metamorphosed footwall hydrothermal alteration commonly associated with VHMS deposits and are similar to that at the other massive sulphide deposits in the Chisel Lake area.
The top of the host unit is interpreted to be near a decollement contact, where it is overlain by a diverse suite of rocks that include mafic and felsic volcanic and volcaniclastic units, mafic wacke, fragmental units with various grain sizes, as well as crystal tuff units.
The host succession is cut by dykes, the most common of which is a fine grained feldspar-phyric gabbro to diorite. The Chisel Lake pluton, a late 1.8 x 9.8 km layered ultramafic intrusion, truncates the main lens of the Chisel Lake massive sulphide deposit but is not seen in any of the Lalor drill core.
The mineralised bodies are relatively flat lying, trending at 270 to 310° and dipping between 15 and 30° to the north. The orebody has lateral dimensions of ~900 m north-south, x 700 m east-west. Sulphide mineralisation is primarily pyrite and sphalerite. Pyrite occurs as fine to coarse grained crystals ranging from 1 to 6 mm, averaging 2 to 3 in size in the semi-massive to solid massive sulphide sections. Sphalerite is interstitial to the pyrite. A crude lamination of these two sulphide minerals occurs locally. Bands or boudins of coarse grained, near massive sphalerite occur locally strongly suggest that remobilisation occurred during metamorphism.
Disseminated pyrrhotite and chalcopyrite blebs and stringers are locally found within the massive sulphides, adjacent to and generally in the footwall of the massive sulphides. The hydrothermally altered footwall rocks commonly carry some very low concentrations of sulphide minerals.
Some intervals of massive pyrrhotite are also found within the main orebody, although these give way to pyrite-sphalerite mineralised dominant zones.
Six distinct, stacked, zinc rich mineralised zones have been delineated within the Lalor deposit, based on a 4% Zinc Equivalence and minimum 2 m width cut-off. The upper two of these zones (Zone 11 and 10) have higher zinc and iron grades. The footwall lenses, Zones 20, 30, 31 and 40 have moderate to high zinc grades, and are hosted in near solid sulphides containing higher grade gold and locally appreciable amounts of copper. Broadly, Zones 10 (600 x 450 m, elongated north-south) and 20 (900 x 450 m, also elongated north-south) are the most extensive and contain the bulk of the of mineralisation.
The average thickness of the individual ore lenses include: Zone 10 - 9.1 m; Zone 11 - 3.4 m; Zone 20 - 8.9 m; Zone 30 - 11.7; Zone 31 - 7.5 m; Zone 40 - 13 m.
Zones enriched in gold and silver occur near the margins of the zinc rich sulphide lenses and as lenses in local silicified alteration. These gold-rich lenses have been delineated using a 1.0 g/t gold cut-off over a minimum 2 m width, located between 750 and 1480 m below the surface, with a similar general shape to the base metals accumulations, but tending to be more linear.
Remobilisation is indicated in some of the gold-rich zones by late veining that is largely restricted to the massive sulphide lenses. Silicification and the development of gahnite tend to be associated with some of the footwall zones which are often characterised by a copper-gold association, interpreted to be due to higher temperature fluids below a zone of lower temperature base metal accumulation. Fine grain siliceous (±veins ± trace sulphides) and strained stratigraphy tend to be gold rich, although no definitive structural controls of the gold mineralisation has been interpreted, although strong grade variations over short distances and may suggest that the alteration was forming discordant stockwork like zones that are now strongly transposed in the main foliation (Mercier-Langevin, 2009).
The Lalor description is largely drawn from "Carter, R., Schwartz, T., West, S. and Hoover, K., 2012 - Pre-Feasibility Study Technical Report, on the Lalor Deposit, Snow Lake,
Manitoba, Canada"; an NI 43-101 Technical Report prepared for Hudbay Minerals Inc.
Reed Deposit (#Location: 54° 34' 20"N, 100° 38' 20"W)
The Reed Deposit is 20 km WSW of Spruce Lake, 80 km ESE of Flin Flon and 60 km SW of Snow Lake. It is a stratabound massive sulphide deposit that occurs within the Snow Lake assemblage of the Flin Flon-Glennie Complex (see also the separate Flin Flon-Glennie VHMS deposits record for background).
The deposit is overlain by 3 to 7 m of unconsolidated organic and glacial overburden, 15 to 20 m of Ordovician dolomitic limestone, 1 to 2 m of semi-consolidated to consolidated Ordovician quartz rich sandstone, and a 5 to 25 m thick palaeoregolith of deeply weathered volcanic rocks of the 1.89 Ga, Palaeoproterozoic Fourmile Island Assemblage (Bailes, 2010, unpublished).
The Fourmile Island Assemblage consists of at least six main stratigraphic units of lower greenschist facies metamorphic rocks, facing to the NW. The uppermost units of this assemblage, Unit E, composed of aphyric, pillowed to massive mafic flows, and Unit F, which includes aphyric to plagioclase-phyric mafic flows, together are up to 2 km thick. On the basis of geochemical analyses it has been suggested that Unit E is similar to the mafic host rocks of the concealed Reed deposit. The Reed host lithology is logged primarily as basalt with minor rhyolitic quartz-feldspar-porphyry intrusives. The known outcrop of the Fourmile Island Assemblage and the similar hosts at the deposit, have both been subjected widespread silicification. The volcanic rocks of units E and F are on strike with, and may be a lateral continuation of the basalt flows that hosted the past producing Dickstone volcanogenic massive sulphide deposit (Syme et al., 1995).
The Fourmile Island Assemblage metavolcanic rocks are intruded by a 1 km thick compositionally zoned and highly fractionated ~1.886 Ga mafic sill that has undergone extreme iron fractionation.
Mineralisation is generally fine to medium-grained, disseminated to massive sulphides, comprising pyrrhotite, pyrite, chalcopyrite, sphalerite and magnetite. The main gangue minerals are chlorite, and quartz. The deposit is interpreted to comprise three stacked tabular bodies with varying orientations.
• The uppermost, Zone 30, trends 305° and dips 77° to the northeast, and is generally characterised by massive sulphides with elevated gold and silver, and moderate copper and zinc grades.
• Zone 20 trends 300° and dips 71° to the northeast, and is also characterised by massive sulphides consisting of high grade copper, minor zinc and low grade gold and silver.
• Zone 10 trends 275° and dips 80° to the south, and is composed of stringers and disseminated sulphides, which consists of high grade copper and low grade gold, silver and zinc.
Sulphide intersections range from 2.00 up to 72.51 m in core length, and have been followed in drilling over a strike length of 430 m and to depths of 550 m below surface. Mineralisation begins at ~25 m below surface and extends to ~580 m below surface.
Alteration assemblages in the vicinity of the mineralisation include muscovite, tremolite, limonite, biotite, epidote, ankerite, ilmenite and talc.
The Reed description is drawn from "Allen, T., Spence, C., Hatton, M and Christensen, B., 2012 - Pre-Feasibility Study Technical Report on the Reed Copper Deposit, Central Manitoba, Canada"; an NI 43-101 Technical Report prepared for VMS Ventures Inc.
Stall Lake and Rod Deposit (#Location: 54° 51' 10"N, 99° 56' 30"W)
The Stall Lake Mine is located 6.5 km ESE of Snow Lake town, and 3 km east to ENE of Chisel Lake. It commenced production in 1964 and closed in 1994.
The Stall Lake, Rod, Osborne Lake and Anderson Lake orebodies occur in the same acidic pyroclastic sequence, near its contact with overlying amphibolites derived from basic tuffs and flows along the eastern limb of the Threehouse Syncline. This succession belongs to the 'primitive arc', the Anderson sequence, of the Snow Lake assemblage (see the separate Flin Flon-Glennie VHMS deposits record for background). The ores within the Anderson sequence are characterised by high Cu and low Zn grades.
The sequence in the Stall Lake area, is as follows, from oldest to youngest:
• Garnet-biotite Gneiss - representing a wedge of metasedimentary rocks in the southeast corner of the deposit area. Some beds in the gneiss contains minor staurolite.
• Basalt - up to 400 m of relatively massive and fine to medium grained basalt, probably representing thick flows, occurring above the metasedimentary gneisses to the south.
• Rhyolite which is up to 240 m thick in the southwest, but pinches out eastward. Locally, it has highly contorted lamination and banding, interpreted to be primary flow structure associated with viscous extrusion. Other exposures are found locally within the overlying quartz "porphyry" unit with contacts that may be gradational along strike.
• Quartz porphyry - a NE striking, up to 750 m thick unit of a light buff to pinkish, moderately well foliated quartz 'porphyry' with infrequent banding. It contains rounded to lens shaped 'eyes' up to 1 cm across, of clear, commonly bluish coloured quartz, that may constitute up to 20% of the rock, set in a 0.01 to 0.12 mm quartz-feldspar matrix. The 'eyes' are composed of either strained single crystals or mosaic aggregates of finer-grained and relatively strain-free quartz. The foliation in part wraps around the 'eyes' as well as penetrating them. As such they are metacrysts, rather than phenocrysts. It also contains <10% muscovite, with lesser biotite and carbonate, 1% pyrite, and a trace of apatite. The rock has a streaky, somewhat irregular distribution of constituent minerals, interpreted to reflect a pyroclastic protolith. Locally this unit has lesser quartz eyes, but contains indistinct lapilli and occurrences of rhyolitic tuft breccia with well-defined, stretched, cherty rhyolite fragments up to 2 x 30 cm inches in size. This unit hosts the main mineralisation. In the immediate area of the No. 1 deposit, it is more variable with amphibolitic, chloritic and micaceous bands or zones.
• Basic tuff - an ~180 m thick unit of fine-grained, dark-coloured, relatively well banded rocks that are distinctly agglomeratic in places. It is composed of 40 to 45% hornblende and 35% quartz, with lesser plagioclase, epidote, carbonate and minor chlorite, magnetite and rare garnet. Narrow layers contain abundant sheared rhyolite
fragments. Layers up to 50 m thick are also found within the quartz porphyry south of Stall Lake.
• Basalt - up to 700 m of fine grained amphibolite after basalt, commonly with relict flow structures and faint remains of pillows. The predominant mafic constituent is metamorphically derived amphibole, with relatively common to absent garnet. Minor rhyolite interbands are evident.
• Gabbro - occurs as sill-like fine to medium grained syn-volcanic and later, coarse grained, syntectonic intrusions are evident, varying from <5 to 150 m in thickness.
Most volcanic units in this sequence thin to the east. Throughout the deposit area these rocks have a relatively constant average strike of about 45° and dip at 56°NW. The deposit is on the east limb of the Miller Lake syncline, a subsidiary feature on the east limb of the broad, northeast plunging Threehouse syncline, (Harrison, 1948). Foliation is variably developed in the various lithologies. A distinct lineation is evident on the foliation surfaces, with an average plunge of 37° and azimuth of 25°, which parallels the plunge of the No. 2 ore zone.
Greyish-white to buff-coloured carbonate occurs as a ubiquitous alteration of the rocks hosting the ore deposits at Stall Lake, occurring 3 to 6 m and to a lesser degree below the No. 2 ore zone. Carbonate is a prominent gangue constituent in the sulphide ore and late stage veining, which also contains grains of sphalerite or chalcopyrite, and cross-cuts the ore zone.
The sulphide orebodies occur along the crests of folds, and are tabular, striking east-west, dipping at 40 to 45°N, with a northerly plunge. The No. 1 orebody is 76 m long, averages 4.6 m in thickness, and persists down plunge for 680 m. The No. 4 orebody, which is centred 150 m west, along strike from No. 1, is 84 m long and has an average thickness is 6 m, and extends from 503 to >869 m below surface. Two other tabular ore zones occur between No. 1 and No. 4. There are also several disseminated orebodies between surface and 549 m.
The ore at Stall Lake is copper-rich with minor zinc. The sulphide concentrations are in siliceous gneisses/quartz 'porphyry' of pyroclastic origin, near their contact with overlying amphibolites derived from basic tuffs and flows. The main sulphides, in order of abundance, are pyrrhotite, pyrite, chalcopyrite and sphalerite, occurring in coarse grained masses, with some well-formed pyrite crystals as much as 20 cm across. Tabular crystal of marcasite and variable magnetite and ilmenite accompany the sulphides. The magnetite forms large, irregular-shaped crystals that often contain inclusions of pyrite, pyrrhotite or ilmenite. Hexagonal pyrrhotite with chalcopyrite and sphalerite occurs in the upper part of the mine, whilst monoclinic pyrrhotite with pyrite, chalcopyrite, and sphalerite is found in the lower part of the mine. Minor gold and silver are also present. Non-metallic minerals include dark, smoky green cordierite, found with the sulphides, cruciform twins of staurolite, red garnets, blue and grey blades of kyanite, and granular aggregates of epidote with quartz (Phillips, 1979).
The Rod deposit, immediately to the east of the Stall Lake lenses, comprises two further lenses, No. 1 and No. 2. The No. 1 lens has a maximum strike length of ~60 m, is <1 to 7.5 m thick, and extends from surface to a depth of ~75 m, with a dip of 40 to 45°NW, and plunges at 32° along an azimuth of 28°. The larger No. 2 lens has a maximum strike length of ~60 m, averages 3.6 m in thickness, with a down plunge length of 625 m, from a depth of 150 m to ~450 m> The lens a dips at 50 to 60°NW, and plunge at 35°NE above the 300 m level and 25°NE below.
The No. l ore zone of the Rod deposit consisted of a massive lens of chalcopyrite with minor sphalerite, pyrite and arsenopyrite, hosted almost entirely within quartz 'porphyry' but with more layered and variable varieties than elsewhere in the unit. Darker layers contain hornblende, and quartz 'eyes' are less prevalent. In addition to the massive economic sulphides, there are also interspersed within and along strike occurrences of uneconomic sulphides that include: fine-grained almost massive pyrite; coarse-grained mottled pyrite-pyrrhotite in a fine grained chlorite-sericite matrix; finely disseminated pyrrhotite with lesser pyrite; coarse-grained veins containing quartz, vuggy pyrite, pyrrhotite and chalcopyrite; and disseminated sulphides, predominantly pyrite in a coarse-grained biotitic layer.
A barren gap of 220 m down plunge separates the bottom of No. 1 and the top of the No. 2 Ore Zone at the Rod deposit.
The Cu-Zn-rich sulphides of the No. 2 Ore Zone form a high grade core that passes laterally, in the plane of the zone, both up and down dip into non-economic, disseminated sulphides, mainly pyrite, resulting in an apparent width of sulphide development of 120 to 250 m. In contrast, there is an abrupt contact between the ore zone and wall rocks normal to this plane, with disseminated wall rock sulphides passing into massive sulphide ore within <1 m. Within the main ore zone, the average proportion of sulphide minerals
are: chalcopyrite 40%, pyrite 30%, sphalerite 15%, pyrrhotite 12%, arsenopyrite 3%, with minor minor galena and marcasite.
Anderson Lake Deposit (#Location: 54° 51' 40"N, 99° 59' 40"W).
The Anderson Lake deposit is about 3 km SE of Snow Lake town, and 5 km WNW of the Stall Lake mines. The deposit was discovered in 1964, mining commenced on November 9, 1970, and the mine closed in 1988.
The deposit is hosted by the 'primitive arc', the Anderson sequence, of the Snow Lake assemblage, as described in the Stall Lake summary above (see also the separate Flin Flon-Glennie VHMS deposits record for background). The deposit lies on the eastern limb of the district wide Threehouse Syncline. The deposit is immediately hosted by staurolite-garnet-cordierite schists within the rhyolite-quartz 'porphyry' unit, which have been altered to chlorite and sericite schists occur in the wall-rocks. The orebody is tabular-shaped, striking 65° and dipping at 60°NW. It has a length of 823 m down the plunge of 55°N, for an average strike length is 122 m. It deposit occurs from 137 to 808 m below surface, averaging 5.5 m in thickness.
The ore consists of coarsely crystalline pyrite, chalcopyrite and pyrrhotite, with minor amounts of sphalerite and magnetite. Pyrite cubes may be as much as 10 cm in across. Less abundant pyrrhotite is interstitial, as is chalcopyrite, which occurs as blebs in pyrite and silicate minerals. Magnetite is found as crystals and nodules in chlorite schist. Large amounts of grey and blue kyanite are associated with the ore. Gangue minerals also include large crystals of staurolite, almandine and cordierite. Calcite accompanies radiating clusters of green actinolite accompanies massive quartz in the gangue, and coarse flaky aggregates of dark green chlorite are also common. Brown prismatic aggregates of anthophyllite and coarsely cleavable masses of anhydrite can also be found on the mine-dump (Phillips, 1979).
The ore is richer in copper for 0.6 or 0.9 m along the footwall where pyrrhotite is found, and disseminated chalcopyrite and pyrite occur sporadically in chlorite-biotite and quartz-sericite schists. The pyrite contains interstitial chalcopyrite and trace gold and silver.
Osborne Lake Deposit (54° 54' 43"N, 99° 43' 40"W)
The Osborne Lake orebody is the most easterly of the economic massive sulphide deposits of the Snow Lake district of northern Manitoba, 21 km NE of the town of Snow Lake and the Anderson Lake mine. Mineralisation was discovered in 1929, and after sporadic exploration the mine was brought into production on July 2, 1968, and closed in 1984.
The deposit is hosted by felsic volcanic rocks of the 'primitive arc', the Anderson sequence, of the Snow Lake assemblage, as described in the Stall Lake summary above (see also the separate Flin Flon-Glennie VHMS deposits record for background).
The main orebody, which does not outcrop, comprised a tabular lens of massive sulphide, striking 045°, dipping 65°NW and plunging 30°SW, conformable to the enclosing rocks. Both the massive and associated disseminated sulphides occur along the Berry Creek fault zone, on the eastern flank of the district wide Threehouse syncline. The orebody has an average strike length of 232 m (maximum 375 m), averages 6 m in thickness, and extends from the 140 m level for 1100 m down plunge to the 838 m level.
A second, ~0.8 m thick, subparallel, zone of sulphide mineralisation, with 1.0% Cu, 1.9% Zn, underlies the main orebody. It occurs from a depth of of 152 to >640 m, and diverges from the main deposit, being 15 m lower at a depth of 305 m, and 30 m at a depth of 640 m. Both ore-zones and wall-rocks are intruded by coarse, sheared pegmatite.
The ore is coarse-grained and contains more copper than zinc, predominantly composed of pyrrhotite and pyrite with lesser amounts of chalcopyrite and sphalerite. Galena is rare. Sphalerite has a high MnS content. The minor metallic minerals are arsenopyrite, galena and marcasite. An early, overprinted, less prevalent phase of fine-grained pyrite and arsenopyrite has also been recognised. As observed in other highly metamorphosed Fe sulphide ores, pyrrhotite is abundant, and coarse textures without preferred orientation are common (Templeman-Kluit 1970, Bristol 1984). Both hexagonal and monoclinic pyrrhotite are recognised (Bristol 1974). Minor rutile is associated with the ore minerals, whilst red garnets are common in the gneiss, and brown, 1 cm crystals of titanite occur in massive white quartz. Other gangue minerals include bright green mica, smoky brown anthophyllite, greyish-green pyroxene, chlorite, green serpentine and epidote. Massive greyish blue plagioclase and white to greenish feldspar are also present (Bristol and Froese, 1989; Phillips, 1979).
Two alteration zones are mapped in the footwall of the orebody. The first is 6 to 17 m wide, and occurs adjacent to the ore at a depth of 305 m, reappearing again from 396 m to 457 m below the surface. Below 457 m this zone divides, with one arm accompanying the ore to below the 838 m mine level, whilst the greater portion, plunges gently to the NE, away from the orebody. A second zone of alteration, intersected in four drill holes from the 442 m mine level, is about 25 m thick and lies 243 to 275 m from the orebody. It has been traced for a strike length of 243 m (Bristol and Froese, 1989).
New Britannia Deposit (Nor-Acme or Snow Lake Mine) (#Location: 54° 53' 10"N, 100° 1' 24"W)
While this is not a VHMS deposit, similar to those described above, it is of similar age, in the same host rocks and has similar quartz-carbonate alteration and a similar gold grade to some of the VHMS. It therefore follows that it is most likely related the same mineralising event.
Claims were first staked over the Snow Lake area in 1924. After sporadic small scale mining and a number of exploration programs, the Nor-Acme mine commenced operation in 1949, and produced 18.99 t Au from 5.080 Mt of ore at an average grade of 3.8 g/t Au, before closing in 1958. The operation was re-opened as the New Britannia mine in 1995, and recovered 24.9 t Au from 6.096 Mt of ore at an average grade of 4.5 g/t Au, before closing again in 2005. Remaining NI 43-101 compliant measured + indicated + inferred resources in 2010 for what is now the Snow Lake Project, were 7.838 Mt @ 4.23 g/t Au for 33.2 t of contained Au (Genivar Limited Partnership, 2010).
Known gold mineralisation at Snow Lake defines a NNW-SSE elongated corridor of some ~6 x 1.5 km, from the Bounter Zone in the south to the Solidor Zone in the north. However, the corridor may curve east-west from the southern extremity, and then ENE-WSW further to the east with the host sequence, where additional exploration targets have been delineated. The calculated ore reserves are within three of the fourteen known zones along the corridor. These are the: i). New Britannia Zone, 1 km north of the Bounter Zone (which marks the south extremity of the corridor); ii). No. 3 Zone, 1500 m north of the New Britannia shaft; and iii). Birch Zone, 2700 m north of the New Britannia shaft.
This mineralised corridor, and the individual ore zones of the Snow Lake Project are located within the Palaeoproterozoic Flin Flon-Glennie Complex (or Flin Flon Greenstone Belt), an assemblage of polydeformed volcanosedimentary supracrustal sequences intruded by pre- and syntectonic ultramafic and mafic intrusions and syn- to post-tectonic granitoid. The Snow Lake Assemblage surrounding Snow Lake, comprises the succession of intercalated mafic and felsic volcanic and pyroclastic rocks of the Amisk Group, intruded by gabbroic bodies and unconformably overlain by turbidites of the Burntwood Group and arkosic sedimentary rocks of the Missi Group.
The Amisk Group comprises, from the structural base: i). Felsic volcanic rocks, consisting of dacite to rhyodacite flows and volcaniclastic rocks; ii). Porphyritic mafic volcanic and volcaniclastic rocks, made up of three mappable units, pyroxene- and pyroxene-plagioclase-porphyritic tuff to tuff breccia and pyroxene-porphyritic basalt; ii). Mafic volcanic rocks, occupying the structural top of the mine sequence, mainly aphyric basaltic rocks.
A rather irregularly shaped unit of equigranular gabbro intrudes the rhyolite and mafic volcaniclastic rocks in the central portion of the district. This mass contains a weak S2 foliation.
These assemblages have been metamorphosed to low to mid amphibolite facies. For details see the description of this sequence, see the separate Flin Flon-Glennie VHMS deposits record and Beaumont-Smith and Lavigne (2008).
Three periods of deformation have been recognised In the Snow Lake area, all of which are considered to be postdate deposition of the Missi Group (Froese and Moore, 1980). D1 isoclinal folds have been refolded about north-easterly trending D2 open folds (e.g. the district scale Threehouse Syncline). D3 deformation associated with minor folds that postdate D2 folding in the Snow Lake area was observed in the immediate vicinity of gneissic domes on the north margin of the belt and is considered to be related to increased tightening of D2 folds (Froese and Moore, 1980). The NNW trending McLeod Lake thrust fault (Russell, 1957), a major structural break in the Snow lake area, is interpreted to represent an early nappe structure associated with the early isoclinal folding (Froese and Moore, 1980). It is the structural break that locally separates and thrust the 1890 Ma metavolcanic Amisk Group (to the east) over 1845 Ma Burntwood Group metasedimentary rocks (to the west) and defines the western extent of the mineralised corridor at Snow Lake. Some 2 km to the east, a block of 1845 Ma Missi Group rocks has been thrust over the Amisk Group above the east dipping Birch Thrust, forming the eastern limit of the corridor.
The geology and mineralisation of the three main mineralised zones is as follows:
• New Britannia Zone - The gold bearing rocks within the mine lie along a generally east-west trending, curvilinear shear zone, the Howe Sound fault, marked by one or more 'slip planes' accompanied by a variety of altered mylonitic zones. The mylonitic quartz-carbonate-mica zones are predominantly less than 30 cm thick but can locally thicken to between 3 and 6 m. The auriferous quartz carbonate rocks are almost always situated next to, or astride the fault.
The principal mineralisation comprises massive quartz-carbonate alteration/replacement of potassium-altered mafic volcaniclastic rocks adjacent to the contact with felsic volcanic rocks of the Amisk Group. The main carbonate is calcite. The contacts of the mineralised zones are frequently gradational, although sharp fault contacts are evident within some parts of the deposit. A biotite alteration halo occurs within a metre or more of the mineralised zone. The main controls on the distribution of mineralisation are contacts between rocks of differing competency, flexures within the Howe Sound fault, and changes in the dip of the fault plane. The dip of the fault plane averages 45° but may locally vary from 25 to 80°.
At the surface, mineralisation is found over an east-west strike length of ~600 m, occurring in two main zones within the same plane, known as the Toots (west) and Dick (east), respectively. At depth, between the 1030 Level and the 1280 Level the Dick Zone appears to split into two separate zones (Dick and Ruttan), then splits again, so that four zones occur on the 1780 Level, namely from west to east, the Toots, Dick, Ruttan and Hogg Zones. Below the 1780 Level, the Toots Zone is terminated by the McLeod Road Thrust. On the 1780 Level, the Ruttan and Hogg Zones are separated by ~30 m of weak mineralisation, although by the 2010 Level, the two zones have merged, and continue as one, with declining strike length to, and beyond the 2300 Level.
These zones of mineralisation predominantly strike east-west, dip 45°N, following the trend of the Howe Sound fault, and plunge ~030°NNE. The mineralised zones pinch and swelling (boudinaged) in both plan and section.
The main sulphides are arsenopyrite, pyrrhotite and pyrite. Arsenopyrite is ~2% of the mineralisation, pyrrhotite <1% and pyrite <0.25%. Trace sulphides include chalcopyrite and sphalerite with the total sulphide content averaging <5%.
Gold is predominately associated with arsenopyrite, particularly where the arsenopyrite is found as a mesh of fine-grained needles, where gold occurs as minute lenticular masses and veinlets in openings on arsenopyrite crystal boundaries, and within fractures in the arsenopyrite. However, when the arsenopyrite occurs as anhedral grains or massive seams, the ratio of gold to arsenopyrite is less and the corresponding grade of the ore is lower. The gold also occurs as minute particles in quartz and calcite with this generally the case when the gold is visible macroscopically, a very rare occurrence.
• No. 3 Zone - the gold bearing horizons in this zone comprise silicified, quartz rich, shear zones containing arsenopyrite plus gold and occasionally free gold, mostly hosted within brittle basalts and tuffs with varying amounts of quartz, carbonate and argillic alteration. The geology of the mineralised zone is illustrated by its occurrence on the 65 Level, where the primary ore was located in a 0 to 1.5 m thick quartz vein. Mineralisation is not confined to the quartz vein, but also occurs in banded tuffs with biotite, quartz and arsenopyrite alteration that form an ~30 cm wide selvedge to the vein, and in some cases can be up to several metres wide. The gold zone is bounded in the hanging wall by a fault zone marked by several cms of gouge to a mylonite zone up to 60 cm wide. Numerous shears and joints run subparallel to the quartz vein, and foliation can vary wildly, controlling an associated quartz vein stockwork at a low angle to the fault direction.
The main mineralised zone is curvilinear, with the strike varying from 105 to 95° at its northwestern and eastern extremities respectively. It dips from 40 to 45°N and plunges ~40° at an azimuth of 60°. The gold bearing zone is 2 to 11 m thick with a strike length of 200 m. The strike of the foliation is asymmetrical about the veins, with a Z-shape indicating sinistral movement within a brittle-ductile shear zone. The mineralisation in the gold zone is composed of up to 10% medium to fine grained arsenopyrite, from 0% to 5% pyrite, traces of chalcopyrite and up to 5% tourmaline. The highest gold values are correlated to fine grained felted masses of arsenopyrite that commonly occur along the margins of quartz veins (Galley et al., 1986).
• Birch Zone - is interpreted to be hosted in a silicified shear zone, cutting an variety of rock types, including graphitic argillite, siltstone, chert, mafic volcanic rocks (flow, fragmental, and tuff units) and gabbroic to dioritic sedimentary rocks (Taylor. 1989). The mineralised zone dips at 45° and plunges at ~15°. Mineralisation and alteration are very similar to that of the No. 3 Zone. A large shear zone cuts through the main section of the mineralised zone, with several other parallel and sub parallel shears. The gold is generally associated with arsenopyrite but some rare free gold has also been recorded.
Beaumont-Smith and Lavigne (2008) note that on a regional scale at Snow Lake, there is a strong spatial association between gold mineralisation and the McLeod Road Thrust. Gold mineralisation is located in the hanging wall of the thrust and is hosted by a wide variety of rock types. The two common characteristics are the hosting of mineralisation within high-strain zones and along or adjacent to lithological contacts. Mesoscopic overprinting relationships between gold mineralisation and fabric elements constrain gold emplacement to syn-D2 or older. Quartz veins that accompanied gold emplacement at the No. 3 Zone (and adjacent Kim Zone) are both folded by F2 and locally cut F2 axial planes, suggesting gold emplacement
coincides with D2, which would also coincide with the peak of metamorphism. This represents a minimum relative age for gold mineralisation, although an older relative age is indicated by the correlation between intense S1 development along lithological contacts and gold emplacement along the same horizons.
The Snow Lake / New Britannia description is largely drawn from "Alexis Minerals Corporation, 2012 - Feasibility Study, Snow Lake Mine Re-activation Project;" an NI 43-101 Technical Report prepared for Genivar Limited Partnership.
Reserve + production figures for these deposits are as follows (after Gibson et al., 2011, except where indicated otherwise):
• Chisel Lake - 7.154 Mt @ 0.54% Cu, 10.6% Zn, 1.76 g/t Au, 44.76 g/t Ag,
• Chisel North - 2.606 Mt @ 0.21% Cu, 9.49% Zn, 0.58 g/t Au, 21.43 g/t Ag, ~1 km NE of Chisel Lake
• Chisel Open-pit - 1.0 Mt @ 0.25% Cu, 8.5% Zn, 2.74 g/t Au, 54.86 g/t Ag, (Syme and Bailes, 1993), ~0.5 km S of Chisel Lake
• Ghost & Lost - 0.581 Mt @ 1.34% Cu, 8.6% Zn, 1.2 g/t Au, 39.09 g/t Ag, ~1 km ESE of Chisel Lake
• Reed - 7.154 Mt @ 0.54% Cu, 10.6% Zn, 1.76 g/t Au, 44.76 g/t Ag, (Indicated resource, VMS Ventures, 2012) - 52 km SW of Chisel Lake
0.170 Mt @ 4.26% Cu, 0.52% Zn, 0.38 g/t Au 4.55 g/t Ag (Inferred resource, VMS Ventures Inc., 2012)
• Lalor - 14.048 Mt @ 0.71% Cu, 8.96% Zn, 1.79 g/t Au, 27.49 g/t Ag, (indicated resource, Schwartz et al., 2012) - 10 km N of Chisel Lake
2.729 Mt @ 0.39% Cu, 0.43% Zn, 4.31 g/t Au, 22.27 g/t Ag, (indicated Au resource, Schwartz et al., 2012)
3.817 Mt @ 0.60% Cu, 9.09% Zn, 1.20 g/t Au, 22.15 g/t Ag, (inferred Cu-Zn resource, Schwartz et al., 2012)
7.338 Mt @ 0.41% Cu, 0.32% Zn, 4.64 g/t Au, 31.35 g/t Ag, (inferred Au resource, Schwartz et al., 2012)
1.461 Mt @ 4.15% Cu, 0.31% Zn, 6.80 g/t Au, 20.33 g/t Ag, (inferred Cu-Au resource, Schwartz et al., 2012)
• Dickstone - 1.077 Mt @ 3.91% Cu, 2.15% Zn, 1.56 g/t Au, 9.49 g/t Ag, - 25 km west of Chisel Lake
• Stall Lake - 6.381 Mt @ 4.41% Cu, 0.5% Zn, 1.41 g/t Au, 12.34 g/t Ag, - 3 km east to ENE of Chisel Lake
• Rod - 0.735 Mt @ 6.63% Cu, 2.9% Zn, 1.71 g/t Au, 16.11 g/t Ag, - immediately ENE of Stall Lake
• Anderson Lake - 2.510 Mt @ 3.4% Cu, 0.1% Zn, 0.62 g/t Au, 7.54 g/t Ag, - 9 km ENE of Chisel Lake
• Osborne Lake - 2.807 Mt @ 3.14% Cu, 1.5% Zn, 0.27 g/t Au, 4.11 g/t Ag, - 29 km east to ENE of Chisel Lake
• Snow Lake/New Britannia - 11.176 Mt @ 4.8 g/t Au, (Cumulative production, Genivar, 2010), - 8 km NE of Chisel Lake
5.471 Mt @ 4.14 g/t Au, (Measured+indicated resource, Genivar, 2010)
2.367 Mt @ 4.43 g/t Au, (Inferred resource, Genivar, 2010).
Reserve + production figures for the other significant and satellite deposits of the Snow Lake district are listed in the Flin Flon-Glennie Complex VHMS Deposits record.
The most recent source geological information used to prepare this decription was dated: 2012.
Record last updated: 15/11/2014
This description is a summary from published sources, the chief of which are listed below.
© Copyright Porter GeoConsultancy Pty Ltd. Unauthorised copying, reproduction, storage or dissemination prohibited.
Chisel Lake Lalor Britannia
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Selected References:
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Bailes, A. H., Galley, A.G., Paradis, S. and Taylor, B. E., 2016 - Variations in Large Synvolcanic Alteration Zones at Snow Lake, Manitoba, Canada, with Proximity to Associated Volcanogenic Massive Sulfide Deposits: in Econ. Geol. v.111, pp. 933-962
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Beaumont-Smith C J and Lavigne J, 2008 - Structural geology and gold metallogenesis of the New Britannia mine area, Snow Lake, Manitoba (NTS 63K16);: in Report of Activities 2008, Manitoba Geological Survey, Manitoba Science, Technology, Energy and Mines, GS-1 pp. 717
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Bristol C C and Froese E, 1989 - Highly metamorphosed altered rocks associated with the Osborne Lake volcanogenic massive sulfide deposit, Snow Lake area, Manitoba: in The Canadian Mineralogist v.27 pp. 593-600
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Coats C J A, Clark L A, Buchan R and Brummer J J, 1970 - Geology of the Copper-Zinc Deposits of Stall Lake Mines Ltd., Snow Lake Area, N. Manitoba: in Econ. Geol. v.65 pp. 970-984
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Gagne S, Beaumont-Smith C J, Williams-Jones A E and Hynes A, 2007 - Investigation of a Pb-Ag-Aurich hangingwall in lens 4 of the Chisel North mine, Snow Lake, Manitoba (NTS 63K16): preliminary results: in Report of Activities 2007, Manitoba Geological Survey Manitoba Science, Technology, Energy and Mines GS-4 pp. 4350
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Gagne S, Beaumont-Smith C J, Williams-Jones A E and Hynes A, 2006 - Metallogenic and metamorphic study of selected deposits from the Snow Lake area and the southern flank of the Kisseynew Domain, Manitoba (NTS 63K16 and 63N2): in Report of Activities 2006, Manitoba Geological Survey, Manitoba Science, Technology, Energy and Mines, GS-4 pp. 42-48
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Rubingh, K.E.L., Lafrance, B. and Gibson, H.L., 2024 - The Snow Lake Deposits in Manitoba, Canada: Formation of Metamorphosed Amphibolite Facies Orogenic Gold Deposits During a Progressive and Prograde Orogenic Event: in Econ. Geol. v.119, pp. 421-444. doi: 10.5382/econgeo.5048
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Skirrow R G, Franklin J M 1994 - Silicification and metal leaching in semiconformable alteration beneath the Chisel Lake massive sulfide deposit, Snow Lake, Manitoba: in Econ. Geol. v 89 pp 31-50
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