Ontario Mineral Inventory

Ontario Geological Survey
Permanent Link to this Record: MDI42E03SW00031

Record: MDI42E03SW00031

General

Commodities

Primary Commodities: Copper, Gold

Secondary Commodities: Silver

Location

Township or Area: Rope Lake Area

Latitude: 49° 0' 26.11"    Longitude: -87° 15' 28.36"

UTM Zone: 16    Easting: 481141   Northing: 5428294    UTM Datum: NAD83

Resident Geologist District: Thunder Bay South

NTS Grid: 42E03SW

Point Location Description: Shaft

Location Method: Field Visit

Access Description: The occurrence is located on the north shore of Big Duck Lake, approximately 25 km north of Schreiber (claim map G-609). Easiest access is by aircraft from Pays Plat or Thunder Bay to Big Duck Lake. A drill road from the Winston Lake Mine leads to Big Duck Lake.

Exploration History

Pre-1964: Shaft/pit sunk. 1983: Airborne geophysical survey (EM, MAG); Noranda. Property examination and lithogeochemical sampling; OGS Resident Geologist staff. 1983-1987: Geological, geochemical and ground geophysical (MAG, EM) surveys and diamond drilling (including 1 DDH on the Helin Shaft area totalling 150 m); Corporation Falconbridge Copper. 1993: Diamond drilling (totalling 2163 m); Metall Mining Corporation and Rusty Lake Resources. The drilling was done in the surrounding area, primarily in the vicinity of the Coco-Estelle and Nelson Pit showings. 2003: Prospectors S. Stares, M. Stares, and H. Critchley carried out prospecting and sampling.

Assessment Work on File

Geology

Province: Superior

Subprovince: Wawa

Terrane: Wawa-Abitibi

Belt: Schreiber-Hemlo

Geological Age: Archean  

Geology Comments

Dec 07, 2005 (D McKay) - Schnieders et al. (1996) describe the local geology as follows: A 9 m long by 3 m wide trench or pit was observed at this occurrence. The trench trends 135 to 140 degrees. A small dump is present indicating the presence of a shaft. The host rocks consist of a quartz porphyry unit which displays evidence of intense shearing, silicification, sericitization and pyritization. This zone of shearing, sericitization and pyritization appears to be up to 6 m but the strike length was not determined due to overburden cover.

Lithology

Lithology Comments

Dec 07, 2005 (D McKay) - The host rocks consist of a quartz porphyry unit which displays evidence of intense shearing, silicification, sericitization and pyritization.

Mineralization

Mineralization Comments

Dec 07, 2005 (D McKay) - Schnieders et al. (1996) state: The mineralized zone consists of sericite schist with sections containing up to 75 percent pyrite mineralization. Minor chalcopyrite and a green mica were also observed. The foliation has an orientation of between 200 and 260 degrees and has a dip of approximately 60 degrees towards the north. Numerous narrow quartz veins are present within and close to the mineralized zone, and closely parallel to the foliation. Mineralization occurs as disseminated pyrite and as small stringers of pyrite. Minor chalcopyrite also occurs. The host rock appears barren of sulphides within 3 to 4 metres of the mineralized shear zone. Wells (1984, assessment files) provides the following comments regarding the occurrence: The host rock is a QP but the material in the trench is so highly silicified that it is difficult to see the quartz phenocrysts. Disseminated pyrite (3-3% and locally 20%) and traces of chalcopyrite are associated with the alteration. The exposure in the area is quite poor and thus it was not possible to trace this zone along strike. The width of the silicified and pyritized zone is estimated to be at least 5 to 6 metres in the trench area. Grab samples collected from the occurrence in 1983 by OGS Resident Geologist staff returned assay values which varied from 0.01 to 0.02 opt Au, <0.10 to 0.30 opt Ag, 0.02 to 0.17% Cu, trace Pb and trace Zn. Wells (1984, assessment files) conducted grab and chip sampling on the mineralized zone. The highest grab sample was TBD 527 which assayed 544 ppb Au and contained 5-10% disseminated pyrite. Sample TBS 1290 was a 2.55 m chip sample that assayed 473 ppb Au and 1245 ppm Cu.

Jun 13, 2019 (Therese Pettigrew) - Samples collected in 2003 by the Stares brothers returned values ranging from 17 to 526 ppb Au (Assessment report 42E03SE2003).

Alteration Comments

Dec 07, 2005 (D McKay) - The host rocks consist of a quartz porphyry unit which displays evidence of intense shearing, silicification, sericitization and pyritization.

Mineral Record Details

References

File - Schreiber-Hemlo Resident Geologist Mineral Deposit Files

Publication Number: Min Dep Date: 1996

Author:

Publisher Name:

Location: Thunder Bay RGP

Map - Nipigon-Schreiber, geological compilation series, Thunder Bay District

Publication Number: M2232 Scale: 1:253,440    Date: 1973

Author: Carter M.W., McIlwaine W.H., Wisbey P.A.

Publisher Name: Ontario Division of Mines

Location:

Mono - Mineral Occurrences in the Nipigon-Marathon Area, Volumes 1 and 2.

Publication Number: OFR5951 Page: 838-840  Date: 1996

Author: Schnieders B.R., Smyk M.C., Speed A.A., McKay D.B.

Publisher Name: Ontario Geological Survey

Location:

Map - Big Duck Lake area, District of Thunder Bay

Publication Number: M2023 Scale: 1:15,840    Date: 1997

Author: Pye E.G.

Publisher Name: Ontario Dept. of Mines

Location:

MonoMap - Mineral deposits of the Big Duck Lake area, District of Thunder Bay

Publication Number: R027 Date: 1997

Author: Pye E.G.

Publisher Name: Ontario Dept. of Mines

Location:

Map - Schreiber-Duck Lake area, District of Thunder Bay

Publication Number: ARM30A Scale: 1:63,360    Date: 1998

Author: Hopkins P.E., Tanton T.L.

Publisher Name: Ontario Dept. of Mines

Location:

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Ministry Contact Information

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