Ontario Geological Survey
Permanent Link to this Record:
MDI42D13SW00006
| Record Name(s) | St. Ignace Harbour - 1980, Otter Bay Copper - 1955, Horlak Mines Ltd - 1955 |
|---|---|
| Related Record Type | Partial |
| Related Record(s) | |
| Record Status | Occurrence |
| Date Created | 1980-Jan-21 |
| Date Last Modified | 2022-May-06 |
| Created By | |
| Revised By |
Primary Commodities: Copper
Secondary Commodities: Gold
Township or Area: St. Ignace Island Area
Latitude: 48° 46' 29.52" Longitude: -87° 46' 57.33"
UTM Zone: 16 Easting: 442501.828 Northing: 5402724.66 UTM Datum: NAD83
Resident Geologist District: Thunder Bay South
NTS Grid: 42D13SW
Point Location Description: 2 pits, 8 diamond drill holes.
Location Method: Conversion from MDI
Access Description: The St. Ignace Harbour occurrence is located on the eastern shore of St. Ignace Harbour of St. Ignace Island. The occurrence is on the north side of Bead Island Channel. The property is accessible by boat, with boat launches available at Nipigon, Rossport and Gurney-by-the-Sea Resort.
1955: Horlak Mines Limited conducted trenching, sampling and diamond drilling. Two pits were excavated on the mineralized zones; the northern zone pit was 4' x 6' x 9' deep, while the southern pit was 7' x 6' x 10' deep. A total of 8 diamond drill holes (160 m total) were drilled. 1985: The waters of Lake Superior were withdrawn from staking.
| Office File Number | Online Assessment File Identifier | Online Assessment File Directory |
|---|---|---|
| 11 | 42D13SW8303 | 42D13SW8303 |
Province: Southern
Supergroup: Keweenawan Supergroup
Geological Age: Paleoproterozoic
Dec 07, 2005 (B Nelson) - The occurrence is classed as a 'polymetallic vein, volcanic-hosted copper' deposit. The area is underlain by amygdaloidal basalt flows of Osler Group. The Otter Lake Fault strikes through St. Ignace Harbour at approximately 330 degrees. Two mineralized zones in amygdaloidal basalt were tested. The northern zone observed by Resident Geologist staff consists of a 9 m wide zone containing disseminated chalcocite. The southern zone is 120 m southeast of the north zone, with a width of 4 to 8 m, and contains individual veins with an average copper content of 0.3%. Individual calcite veins up to 15 cm wide, striking 280 degrees and dipping 78 degrees south, were observed.
| Rock Type | Rank | Composition | Texture | Relationship | Mafic lava flow-unsubdivided | 1 | Basalt | Amygdaloidal | Host |
|---|---|---|---|---|
| Vein | 2 | Calcite | Host |
| Rank | Mineral Name | Class | Economic Mineral Type | Alteration Mineral Type | Alteration Ranking | Alteration Intensity | Alteration Style |
|---|---|---|---|---|---|---|---|
| 1 | Chalcocite | Economic | Ore | ||||
| 2 | Malachite | Economic | Ore | ||||
| 3 | Hematite | Economic | Ore | ||||
| 1 | Calcite | Economic | Gangue | ||||
| 2 | Quartz | Economic | Gangue | ||||
| Calcite | Alteration | Hydrothermal | 1 | Unknown | Veins | ||
| Quartz | Alteration | Silicification | 2 | Unknown | Veins |
Dec 07, 2005 (B Nelson) - The southern zone contains individual veins with an average copper content of 0.3%. Resident Geologist staff collected a sample of malachite-stained calcite-quartz vein that assayed 0.015 oz/ton Au, nil Ag and 0.58% Cu.
Apr 29, 2019 (Therese Pettigrew) - Two mineralized zones, striking about N45E, have been located in flat-lying Keweenawan amygdaloidal lavas. The north zone, tested by three drill holes over a length of 175 feet (53.3 m), consists of a steeply-dipping body of calcite stringers over a width of about 30 feet (9.1 m). The calcite stringers contain chalcocite, which also occurs as amygdule fillings, and disseminated grains in the lava, between and bordering the calcite stringers. The south zone lies 400 feet (121.9 m) southeast of the north zone. It is of similar character and has been tested by five drill holes over a length of 1,000 feet (305 m). The holes were all bored from southeast to northwest at angles of 45 degrees and intersected mineralized rock over core lengths ranging from 11 to 26 feet (Shklanka, 1969).
Date: Feb 06, 1997
Geologist: B Nelson
Notes: Resident Geologist staff visited the occurrence August 19, 1992.
Map - St. Ignace Island and adjacent islands, Thunder Bay District
Publication Number: M2285 Scale: 1:63,360 Date: 1974
Author: Giguere J.F.
Publisher Name: Ontario Division of Mines
Location:
Mono - Copper, nickel, lead and zinc deposits in Ontario (revised to February, 1957)
Publication Number: MDC002 Page: 51 Date: 1957
Author: Thomson J.E., Ferguson S.A., Johnston W.G.Q., Pye E.G., Savage W.S., Thomson R.
Publisher Name: Ontario Dept. of Mines
Location:
File - Schreiber-Hemlo Resident Geologist Mineral Deposit Files, Thunder Bay office
Publication Number: Min Dep Date:
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 - Copper, nickel, lead and zinc deposits of Ontario
Publication Number: MDC012 Page: 325-326 Date: 1969
Author: Shklanka R.
Publisher Name: Ontario Dept. of Mines
Location:
MonoMap - Geology of St. Ignace Island and adjacent islands, District of Thunder Bay
Publication Number: R118 Page: 29 Date: 1975
Author: Giguere J.F.
Publisher Name: Ontario Division of Mines
Location:
Mono - Mineral Occurrences in the Nipigon-Marathon Area, Volumes 1 and 2.
Publication Number: OFR5951 Page: 110-111 Date: 1996
Author: Schnieders B.R., Smyk M.C., Speed A.A., McKay D.B.
Publisher Name: Ontario Geological Survey
Location:
We are continuously updating our assessment file / technical report information. If you notice errors in the data, please contact us.
Please review our Terms of Use agreement for this data product.
For detailed information regarding this mineral record please contact the Thunder Bay South Resident Geologist District Office