Ontario Mineral Inventory

Ontario Geological Survey
Permanent Link to this Record: MDI52A11SW00007

Record: MDI52A11SW00007

General

Mineral Record Identification
Record Name(s) Thunderhead Gold Mine - 1950
Related Record Type Partial
Related Record(s)
Record Status Prospect
Date Created 1979-Jul-23
Date Last Modified 2022-May-11
Created By
Revised By

Commodities

Primary Commodities: Gold, Platinum Metals, Copper

Secondary Commodities: Iron, Nickel, Silver, Zinc



Location

Township or Area: Gorham

Latitude: 48° 32' 15.51"    Longitude: -89° 17' 29.18"

UTM Zone: 16    Easting: 330858   Northing: 5378595    UTM Datum: NAD83

Resident Geologist District: Thunder Bay South

NTS Grid: 52A11SW

Point Location Description: Precise

Location Method: Field Visit with GPS

Access Description: Proceed along Hazelwood Road 18 km north of Highway 102 (Red River Road) to Peterson Road. Adit is 10 m from road on west side.



Exploration History

1945-46: Macassa Gold Mines Ltd. drilled 12 DDH totalling 575 m. 1950: Thunderhead Gold Mines Ltd. conducted line cutting and a magnetometer survey. 1961-62: Thunderhead drilled 5 DDH totalling 632 m and drove an adit 80 m. 2005: Kennecott drilled 3 DDH totalling 902 m. 2007: Geoinformatics Exploration Canada Ltd. drilled 4 DDH totalling 1904 m.


Assessment Work on File

Assessment Work on File
Office File Number Online Assessment File Identifier Online Assessment File Directory
63.231 52A11SW0016 52A11SW0016
2.34638 20000002091 20000002091

Geology

Province: Superior

Subprovince: Wawa

Terrane: Wawa-Abitibi

Belt: Shebandowan

Geological Age: Archean  



Lithology

Lithology Data
Rock Type Rank Composition Texture Relationship
Mafic lava flow-unsubdivided 1
Felsic lava flow-unsubdivided 2
Gabbro 3
Vein 4 Host

Lithology Comments

Dec 16, 2015 (Therese Pettigrew) - The layered gabbro intrusion is approximately 1 km x 1 km and is interpreted to be 350 m deep. All of the 2007 drill holes were collared in a leucogabbro to melanogabbro phase. It consists of 40-70% plagioclase (medium-coarse grained with reddish oxidized surface) and 25-60% fine grained mafics (mainly clinopyroxene). The gabbro is underlain by a fine grained black-green peridotite (80% mafics and 20% plagioclase) sometimes with cumulate texture. Altered serpentine (chrysotite and lizardite) + chlorite-epidote zones are often present along fractures and can be pervasive (AFRI 20000002091).




Mineralization

Mineralization and Alteration
Rank Mineral Name Class Economic Mineral Type Alteration Mineral Type Alteration Ranking Alteration Intensity Alteration Style
1ChalcopyriteEconomicOre
2GoldEconomicOre
3PyriteEconomicOre
4PyrrhotiteEconomicOre
5SphaleriteEconomicOre
6MagnetiteEconomicOre
1PlagioclaseEconomicGangue
2ClinopyroxeneEconomicGangue

Mineralization Comments

Dec 16, 2015 (Therese Pettigrew) - Ferguson et al. (1971) reports that the No. 1 vein is 157 m long and strikes east. A sample assayed 1.70 oz/t Au and 1.28 oz/t Ag. Southwest of the auriferous stringers, copper and nickel sulphides occur associated with mafic intrusives. The first hole of the 2005 Kennecott program was drilled into a garnet-magnetite skarn. Four metres of 1.7 gpt gold and 0.53% copper at 58 metres (down-hole depth) were intersected. The second and third holes were on the layered gabbro-melanocratic gabbro-peridotite intrusion. Hole 3 intersected 11.8 metres of 0.295 ppm platinum, 0.373 ppm palladium, 0.32% copper, 0.10% nickel and 0.04 ppm gold from 288.6 metres down-hole including 5.5 metres of 0.428 ppm platinum, 0.541 ppm palladium, 0.48% copper and 0.14% nickel from 292.8 metres down-hole. The 2007 drill program results included the following: 14 metres of 0.35 % copper, 0.33 gpt platinum and 0.40 gpt palladium; 20 metres of 0.22 % copper, 0.25 gpt platinum 0.29 gpt palladium; 8 metres of 0.23 % copper, 0.21 gpt platinum 0.34 gpt palladium; and 4 metres of 0.78 % copper, 0.25 gpt platinum 0.29 gpt palladium (AFRI 20000002091). The Thunderhead property hosts the western extension of the gold bearing quartz veins on the Gorham property (MDI52A11SE00006). Surface sampling of the No. 1 vein indicated a grade of 0.63 opt Au across 2.5 feet for a length of 195 feet. The No. 3 vein, possibly the western extension of the Gorham #1 vein, yielded a grade of 0.714 opt Au across 1.8 feet for a length of 250 feet. In 1961-64, a 263 foot adit was driven on strike of the #1 vein, but ended short of the better mineralization part of the vein (AFRI 52A11SW0004).



Mineral Record Details

Classification
RankClassification            
1 Lode (Gold)
2 Magmatic
1 Vein
Characteristics
Rank Characteristic            
2 Massive
1 Vein

References

Book - Canadian Mines Handbook 1977-78, Thunderhead

Publication Number: CMH1977-78 Page: 304  Date: 1978

Author:

Publisher Name:

Location:


Mono - Gold deposits of Ontario, part 1, districts of Algoma, Cochrane, Kenora, Rainy River, and Thunder Bay

Publication Number: MDC013 Page: 274  Date: 1971

Author: Ferguson S.A., Groen H.A., Haynes R.

Publisher Name: Ontario Dept. of Mines and Northern Affairs

Location:


Map - Gorham Township and vicinity, District of Thunder Bay, Ontario

Publication Number: ARM48C Scale: 1:63,360    Date: 1997

Author: Macdonald R.D.

Publisher Name: Ontario Dept. of Mines

Location:


Map - Geological compilation series, Lakehead-Shebandowan sheet, District of Thunder Bay

Publication Number: P0177 Scale: 1:126,720    Date: 1997

Author: Pye E.G., Fenwick K.G.

Publisher Name: Ontario Dept. of Mines

Location:


Report an Error

We are continuously updating our assessment file / technical report information. If you notice errors in the data, please contact us.


Terms of Use

Please review our Terms of Use agreement for this data product.


Ministry Contact Information

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