Details


SMDI #
0663
Current Showing Name
George Lake Zinc Deposit
Historical Showing Names
George Lake Zinc Deposit, George Lake Zn Deposit
Company Name
Eagle Plains Resources Ltd.
Project Name
George Lake
UTM Easting (NAD83 Z13)
573810.2400
UTM Northing (NAD83 Z13)
6370157.5800
NTS Sheet
064E05
TRM (Township-Range-Meridian)
98-11-2
Primary Commodities
Zinc
Associated Commodities
Arsenic, Iron, Lead
Discovery Type
Outcrop Grab
Status
Deposit: Advanced Exploration
Geological Details
The showing, which is located at the southwest end of George (Brakewell) Lake, consists of a grey quartzite zone which strikes 040° and extends over a length of 7,000 ft (2,133 m) and width of 150 to 450 ft (45.7 to 137.2 m). Float and frost heave are the only evidence of the zone as no outcrop is exposed in the area. The zone extends from the southeast side of the bay on George Lake towards the southwest. The sulphides vary from 2 to 30% and consist mostly of sphalerite and pyrite, sparse galena and minor silver. The host rock is dark greyish to almost black and consists of a locally porphyritic quartzite. The area of the showing has been mapped as being underlain by the northeast-trending Compulsion River Belt or Courtenay Lake-Cairns Lake Fold Belt), part of the Wollaston Fold Belt. Meta-argillites are best exposed northwest of George Lake. Pink meta-arkose is found northwest of the meta-argillite and is very poorly exposed. The area is predominantly covered with muskeg. Quartzites and related sediments are found southeast of George Lake, but the oucrop exposure is very poor due to the thick glacial drift cover. Diorites and amphibolites up to 2,000 ft (610 m) wide separate the quartzite horizon from pink, coarse-grained gneissic biotite-granite which underlies the southern portion of the property. The George Lake Deposit, which is concordant with the enclosing host rocks, is a lensoid deposit with a strike length of 2,625 ft (800 m), and a width of up to 131 ft (40 m). The stratiform mineralization is confined to the uppermost 60 m (196.9 ft) quartzite interval of the Souter Lake Formation, immediately below the overlying George Lake Formation argillites and siltstones. This upper contact is sharp. The lower mineralization contact is gradational. The zone of mineralization has been traced over a total strike length of 8.0 km (4.97 miles). Mineralization consists of a concordant lens (800 m by 40 m by 160 m [2624.7 ft X 131.2 ft X 524.9 ft] deep) of white to grey quartzite which contains pyrite, sporadic pyrrhotite, sphalerite, and galena. The sulphides occur as disseminated interstitial grains and fracture fillings that rarely exceed 20% of the rock by volume. The mineralized zone displays a near-symmetrical zonation pattern with a high grade core and a lowering of grade in an outward direction. It was noted that the grade of mineralization decreases sharply beyond a strike length of 2,800 ft (853.4 m) and maximum width of 150 ft (45.7 m). The Lavisall model appears to explain the development of the deposit. The mineralized shallow marine to beach sandstone was capped by an interbedded quartzite and argillite as marine regression occurred. A following marine transgression resulted in the deposition of a impermeable shale and meta-argillite cap. The mineralization appears to be controlled by the local permiability of the quartz arenite or sandstone host. Burial of the host unit to a depth of 1.3 km (0.8 mile) resulted in dewatering of the sediments. The exhalation of highly saline basinal fluid along syngenetic shears leached Pb and Zn from the surrounding country rock. When these warm sulphate-rich fluids reached the base of the shale cap, the fluids were forced laterally into the arenites where they came into contact with cool conate water. Sphalerite, pyrite, pyrrhotite, and minor galena were precipitated into the interstitial spaces in the arenite. This was followed by metamorphism of the quartzites to arenites and by thrust faulting. Basement doming uplifted the Johnston Lake Granite and separated the Courtney-Cairns Belt from the Wollaston Domain. The sediments in the George Lake area were folded into an isoclinal syncline.
Geological Domain
Wollaston
Host Rocks
Host Minerals
Arsenopyrite, Pyrite
Indicators
Exploration History
12/1/2023 Eagle Plains completed soil sampling, mapping and ground truthing of historical work on the recently acquired George Lake project, located 280 km north of La Ronge. The property includes the historical George Lake zinc deposit. (Saskatchewan Exploration and Development Highlights 2023, p.13) 8/16/1988 The area of the showing was first investigated in 1965 by E.F. Partridge who completed an aerial reconnaissance survey to check aeromagnetic highs, structural features and gossans. Subsequent prospecting of interesting areas lead to the discovery of SMDI 549, 554 and 555. Follow-up work by George Flatland, who was prospecting for Partridge, located a series of sphalerite-galena-bearing boulders and 2 sphalerite bearing outcrops as far distant as the south end of George Lake. Reconnaissance prospecting along the northeast-trending Compulsion River Belt continued for the remainder of the season and resulted in the delineation of SMDI 0541. Detailed prospecting was completed over the George Lake sector of the Compulsion River Belt, which surrounds the bay at southwest end of George Lake and extends towards Souter Lake. The showing was located as a result. 18 trenches were excavated but all were found to be useless due to the thickness of the overburden. Two x-ray drill holes totalling 366.3 ft (111.6 m) were completed in the area but no mineralization was intersected. In 1965, 3 claim blocks and 361 mineral claims were staked to cover the possible source and subsequently were optioned to Falconbridge Nickel Mines. In 1966, geological mapping and associated prospecting was carried out over the George Lake claims east, south and west of the southwest end of George Lake, parts of Falconbridge Permit No. 3 and the north half of CBS 3, northeast of Courtney Lake. Ground magnetometer surveys were conducted to aid in mapping since most of the area is covered by glacial drift and/or muskeg. IP and seismic surveys were done in selected areas. The IP anomalies outlined northwest of George Lake are coincident with mag highs and are found to be caused by pyrrhotite and magnetite associated with pyrite. Sulphides and sulphide stain are evident on the surface rocks near these anomalies. One of the 2 seismic profiles run southeast of George Lake indicated shallow overburden conditions. Diamond drilling of 4 holes totalling 11,033 ft (3362.9 m) was completed in the George Lake Claim Group area as well as surficial mapping and a soil sampling survey. A geochemical anomaly was noted at the southeast end of George Lake. The anomalous area overlaps till known to contain large amounts of mineralized float carrying high Pb-Zn values. The shape of the boulder train indicates a nearby source immediately northeast of the boulder train. Diamond drilling of 3 holes totalling 2028 ft (618.1 m) was completed on CBS 3 (the lake C-76 area) to investigate magnetic highs found to be caused by minor pyrite-pyrrhotite in argillite and by garnetiferous biotite schist. Mineralization was discovered in place in October of 1966. In 1967, geological, magnetometer, surficial geology and soil sample surveys were completed to complete the coverage in areas not covered in the 1966 season (AF 64E05-0019). The mag surveys helped to trace the stratigraphy in the overburden covered areas. Compulsion River Mines Ltd. Was incorporated on November 1, 1968 and acquired 235 claims in 3 groups including the George Lake deposit detailed above. In 1968, Great Plains Exploration and Development optioned the property. They completed an airborne EM survey, geological mapping, and ground geophysics. Diamond drilling was completed in 1969 to 1970 to delineate the George Lake deposit. In 1969, Great Plains completed an airborne INPUT survey which covered the showing. Thirty four delineation drill holes were completed on the showing (AF 64E05-0026). In 1970, a ore reserve calculation was released. In 1974, the Saskatchewan Research Council completed a geochemical study over the glacial fan area. In 1977, W. Coombe geologically mapped the showing area for the government of Saskatchewan. In 1990, Falconbridge Ltd. Flew an airborne EM, VLF-EM and magnetic survey which covered the showing (AF 64E05-0004). On 16 November 1991, Compulsion River Mines Ltd. Staked the showing as S-104599. In the same year, they re-logged and re-sampled existing deposit delineation drill holes GL-1 to -35 and -38 to -41 (AF 64E05-0017). In 1994, drill holes GL94-1 and -2 were completed on anomalies located to the east of the showing (AF 64E05-0031). Between 1994 and 1996, No. 337 Sailview Ventures and Far West Mining completed bulk till and soil sampling and ground HLEM and gravity surveys which covered the showing (AF 64E-0017). A 1996 till sample program (AF 64E-0019) indicated a Zn anomaly on the north shore of Brakewell Lake immediately north of the deposit. In November of 1997, S-104599 was allowed to lapse and the showing came open on 1 May 1997. On 21 May 1997, M. Lederhouse staked the showing as S-105626 for Petro Plus Inc. In March of 2002, Odaat Inc. completed a ground magnetic survey over the deposit (AF 64E05-0032). This work remains confidential. On 3 January 2003, the disposition was transferred to Odaat Inc. and on 6 January 2003, Odaat transferred the property to 1018609 Alberta Ltd.
Production History
Reserves and/or Resources
2003-01-01 Geological resource of 2,630,880 tonnes grading 3.67% Zn and0.53% Pb. Summary: Historic reserve (unspecified) of 2,630,880.00 tonne - Lead @ 0.53 % - Zinc @ 3.67 % 1970-01-01 ZONE PERCENT TONS PCT PCT ZN CUTOFF ZN PB _________________________________________ Low grade 1% 5,000,000 2.65 0.38 High grade 2% 2,900,000 3.67 0.53 (high grade zone included in low grade zone) Summary: High Grade: Historic reserve (unspecified) of 2,900,000.00 ton - Lead @ 0.53 % - Zinc @ 3.67 % (Cutoff: 1) Low Grade: Historic reserve (unspecified) of 2,100,000.00 ton - Lead @ 0.53 % - Zinc @ 3.67 % (Cutoff: 1)
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