Ontario Mineral Inventory

Ontario Geological Survey
Permanent Link to this Record: MDI42C13SW00045

Record: MDI42C13SW00045

General

Commodities

Primary Commodities: Zinc, Gold

Secondary Commodities: Copper, Lead

Location

Township or Area: Wabikoba Lake Area

Latitude: 48° 50' 16.65"    Longitude: -85° 51' 18.84"

UTM Zone: 16    Easting: 584001.8   Northing: 5410074.52    UTM Datum: NAD83

Resident Geologist District: Thunder Bay South

NTS Grid: 42C13SW

Point Location Description: Small blast pit

Location Method: Field Visit

Access Description: The Summers Lake sulphide occurrence is located approximately 31.5 km south of Manitouwadge, 1.3 km west-northwest of the western end of Lunny Lake and 500 m north of Summers Lake. The occurrence is situated approximately 10 m west of a small swampy lake known locally as Season Lake. The occurrence is accessible via motor vehicle followed by travel on foot. From Manitouwadge, proceed south along Highway 614 for approximately 38.5 km to a short road which accesses a campsite located adjacent to the north end of Summers Lake. Proceed on foot east and then northeasterly along an old logging (?) road which starts near the campsite and heads to the west shore of Season Lake. Copper-, zinc- and lead-bearing sulphides are reported to occur within a small trench located on the west shore of Season Lake approximately 75 m south of the lake's north end (Montgomery 1983). Zinc-bearing sulphides also occur within a narrow iron formation exposed in a small blast pit located immediately west of the lake approximately 90 m north of its southern end.

Exploration History

1957: Geological mapping; CPR (M. Bartley, T. Page). 1962: Line cutting, geological mapping, ground geophysical surveys (MAG HLEM); McIntyre Porcupine Mines Ltd. 1964: Geological mapping, lithogeochemical sampling, airborne geophysical survey (MAG, EM); Caravelle Mines Ltd. 1964-1965: Geological mapping; ODM (V.G. Milne). 1966: Ground geophysical survey (MAG); Falconbridge Nickel Mines Ltd. 1967-1969: Diamond drilling (19 holes); Falconbridge Nickel Mines Ltd. 1978-1979: Lake sediment and water geochemical sampling; GSC and MNR. Samples collected from the vicinity of the occurrence contained slightly anomalous amounts of Cu, Zn, Au and Mo. 1983: Line cutting, ground geophysical surveys (MAG, VLF-EM), soil geochemical sampling and geological mapping; Key Lake Exploration Limited. Line cutting, ground geophysical surveys (MAG, VLF-EM, IP), soil geochemical sampling, geological mapping, trenching (?) and diamond drilling (5 holes totalling 520 m); Harlin Resources Limited. Copper- and zinc-bearing sulphides were discovered at this time along the west shore of a small swampy lake referred to locally as Season Lake. Airborne geophysical survey (HLEM, VLF-EM, MAG); Aerodat Ltd. 1985: Geological mapping; OGS (G.M. Siragusa and K.M. Chivers). Key Lake Exploration Ltd. and Brandy Brook Mines Ltd. conducted ground VLF-EM and magnetometer surveys, mapping, and sampling. 1991: Reconnaissance till sampling; GSC (I.M. Kettles). Samples collected in the general vicinity of the occurrence were found to contain slightly anomalous amounts of Cu. 1992-93: Line cutting, ground geophysical surveys (MAG, VLF-EM, Beep Mat), geological mapping and shallow trenching; prospector P. Simoneau. This work resulted in the discovery of a narrow, folded, banded iron formation containing up to 25% sulphides which returned assay values up to 3360 ppm Zn. 1993: Lithogeochemical sampling; OGS (D.B. McKay). 2011: Entourage Metals Ltd. carried out soil sampling.

Assessment Work on File

Geology

Province: Superior

Subprovince: Wawa

Terrane: Wawa-Abitibi

Belt: Schreiber-Hemlo

Geological Age: Archean  

Metamorphism Type: Regional

Metamorphism Grade: Amphibolite

Geology Comments

Dec 07, 2005 (D McKay) - The Summers Lake sulphide occurrence is located in the Wawa Subprovince approximately 17 km north-northeast of the Hemlo mines. The area surrounding the occurrence is underlain primarily by a northeasterly-trending sequence of mafic to felsic metavolcanic and lesser metasedimentary rocks which comprise portion of the the north limb of the Schreiber-Hemlo greenstone belt (Milne 1968, Map 2147; Siragusa and Chivers 1986, Map P.3046). In the vicinity of the occurrence, the belt has been folded into a large easterly-plunging anticline (Milne 1968, Map 2147). The occurrence is located along the south limb of this structure. The supracrustal rocks in this area are locally strongly foliated (45 to 60 degrees/subvertical) and mineral assemblages indicate they have experienced lower amphibolite facies-grade regional metamorphism (Milne 1968). In the vicinity of the occurrence, the supracrustal sequence is approximately 7.5 km wide and is bounded to the north, south, east and west by granodioritic rocks of the Black-Pic Batholith, the Musher Lake Pluton, the Dotted Lake Batholith and the Gowan Lake Pluton, respectively (Milne 1968, Map 2147). The northern portion of the belt is dominated by massive to pillowed basalts which are overlain to the south by intermediate to felsic pyroclastic rocks containing minor metasedimentary interbeds (Milne 1968). The supracrustal sequence dips steeply to the southeast and has been interpreted to young in the same direction (Milne 1968; Baker 1986). The occurrence is located approximately 1 km south of the intersection between the Pinegrove Lake and Jenny Creek faults, two large-scale structures which trend north- westerly and northerly, respectively. In the vicinity of the occurrence, the metavolcanic and metasedimentary rocks have been intruded locally by diabase and felsic dikes of variable composition. The occurrence is hosted within a narrow, banded, sulphide-bearing oxide- facies iron formation.

Lithology

Lithology Comments

Dec 07, 2005 (D McKay) - The iron formation is approximately 1 m wide, is thinly laminated, complexly folded, locally strongly magnetic, locally garnetiferous (containing up to 10% coarse-grained, purple porphyroblasts of garnet) and contains up to 25% fine- to medium-grained pyrite and pyrrhotite concentrated in mafic layers. Trace amounts of sphalerite and chalcopyrite occur as disseminated grains within the iron formation. The feldspar porphyry and diabase dykes in the area are strongly magnetic and the diabase contains up to 5% pyrite and pyrrhotite.

Mineralization

Mineralization Comments

Dec 07, 2005 (D McKay) - Up to 25% fine- to medium-grained pyrite and pyrrhotite and trace amounts of sphalerite and chalcopyrite occur as disseminated grains within the mafic layers comprising the iron formation. Grab samples collected from the occurrence in 1992 by D. McKay for the OGS returned assay results of 517 ppm Cu and 3360 ppm Zn. Several iron formation-hosted base metal occurrences are located within the north limb of Heron Bay-Hemlo greenstone belt in the general vicinity of the Summers Lake sulphide occurrence (e.g., the Jenny Creek, Qued QT-09, Armand Lake, Spruce Bay and Fairservice zinc occurrences). To date, none of these occurrences has proved to be economic. Most of the previous exploration in the area however, has focused on gold mineralization and the base metal potential of this area is not fully understood.

Mar 27, 2019 (Therese Pettigrew) - Muir (2000) reported that this showing returned up to 0.49% Zn in a chert argillite, with up to 20% disseminated pyrite, pyrrhotite, and trace chalcopyrite and sphalerite. The Season Lake south showing, located at NAD83 UTM Zone 16, 584205 m E, 5409873 m N, returned up to 0.35% Zn and 1.03 ppm Au from narrow, sulphide-rich, complexly folded banded iron formation.

Mineral Record Details

References

File - Schreiber-Hemlo Resident Geologist Mineral Deposit Files

Publication Number: Min Dep Date:

Author:

Publisher Name:

Location: Thunder Bay RGP

Map - Black River area, southwest part, District of Thunder Bay

Publication Number: P0334 Scale: 1:31,680    Date: 1997

Author: Milne V.G.

Publisher Name: Ontario Dept. of Mines

Location:

Mono - Mineral Occurrences in the Manitouwadge Area, Volumes 1, 2 and 3

Publication Number: OFR5906 Page: 203-211  Date: 1994

Author: McKay D.B.

Publisher Name: Ontario Geological Survey

Location:

Map - White Lake sheet, Thunder Bay District

Publication Number: M2147 Scale: 1:31,680    Date: 1968

Author: Milne V.G.

Publisher Name: Ontario Dept. of Mines

Location:

MonoMap - Geology of the Black River area, District of Thunder Bay

Publication Number: R072 Date: 1968

Author: Milne V.G.

Publisher Name: Ontario Dept. of Mines

Location:

Map - Geological series, Precambrian geology, White Lake (Hemlo) area, Dotted Lake and Black River sections, District of Thunder Bay

Publication Number: P3046 Scale: 1:15,840    Date: 1986

Author: Siragusa G.M., Chivers K.M.

Publisher Name: Ontario Geological Survey

Location:

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For detailed information regarding this mineral record please contact the Thunder Bay South Resident Geologist District Office