Ontario Geological Survey
Permanent Link to this Record:
MDI42E03SW00009
| Record Name(s) | Gray Occurrence - 1980 |
|---|---|
| Related Record Type | Simple |
| Related Record(s) | |
| Record Status | Occurrence |
| Date Created | 1980-Jan-14 |
| Date Last Modified | 2022-May-09 |
| Created By | |
| Revised By |
Primary Commodities: Gold
Township or Area: Rope Lake Area
Latitude: 49° 0' 35.38" Longitude: -87° 15' 7.78"
UTM Zone: 16 Easting: 481560 Northing: 5428579 UTM Datum: NAD83
Resident Geologist District: Thunder Bay South
NTS Grid: 42E03SW
Point Location Description: Outcrop located along the side of a ravine.
Location Method: Field Visit
Access Description: The occurrence is located approximately sixty-one metres north of the east end of Big Duck Lake approximately 27 km north of Schreiber (claim map G-617). Easiest access is by aircraft from Pays Plat to Big Duck Lake. A drill trail leads from the Winston Lake Mine site to Big Duck Lake.
1950: E.O. Peltonen staked the showing. 1982: Staked by Noranda Exploration Company Ltd. 1983: Property examination and lithogeochemical sampling; OGS Resident Geologist staff. Interest transferred to Corporation Falconbridge Copper. 1984: Geological, geochemical and geophysical (MAG,EM) surveys; Corporation Falconbridge Copper. 2006-7: Tri Gold Resources Corp. carried out mapping.
| Office File Number | Online Assessment File Identifier | Online Assessment File Directory |
|---|---|---|
| 2.7632 | 42E03SE8252 | 42E03SE8252 |
| 2.36089 | 20000002793 | 20000002793 |
Province: Superior
Subprovince: Wawa
Terrane: Wawa-Abitibi
Belt: Schreiber-Hemlo
Geological Age: Archean
Dec 07, 2005 (D McKay) - Pye (1964, p.34) described the Gray occurrence as follows: The Gray vein is found a few hundred feet north of the east end of Big Duck Lake, on ground presently held by J.S. Grant of Toronto. It is exposed along the northeast wall of a narrow northwest-trending ravine. The vein, which is 4.5 feet thick is made up of white to grey, granular quartz with little pyrite. It can be traced only for about 10 feet before it becomes concealed by overburden. It strikes N80 degrees W and dips 50 degrees N. A channel sample across the full width of the vein, assayed by the Provincial Assay Laboratory, indicated only a trace of gold to be present. Schnieders et al. (1996) state: Quartz veins up to 1.2 m wide and sulphide zones were observed hosted by massive to pillowed metavolcanic flows. The metavolcanic rocks are highly foliated, with foliation striking 58 degrees and display epidote, actinolite and biotite alteration. One quartz vein was observed striking 260 degrees and dipping 50 to 60 degrees N. The narrow sulphide zone (~15 cm) contains up to 5% pyrite. The gossan zone also appears to contain an iron carbonate. Several old pits were observed in the vicinity. A narrow quartz porphyry dike was observed to the south of pits.
| Rock Type | Rank | Composition | Texture | Relationship | Mafic lava flow-unsubdivided | 1 | Massive To Pillowed Flows | Host |
|---|---|---|---|---|
| Vein | 2 | Quartz | Host | |
| Quartz Porphyry | 3 | dyke | Near |
| Rank | Mineral Name | Class | Economic Mineral Type | Alteration Mineral Type | Alteration Ranking | Alteration Intensity | Alteration Style |
|---|---|---|---|---|---|---|---|
| 1 | Pyrite | Economic | Ore | ||||
| 2 | Chalcopyrite | Economic | Ore | ||||
| 1 | Quartz | Economic | Gangue | ||||
| Quartz | Alteration | Hydrothermal | 1 | Unknown | Veins | ||
| Epidote | Alteration | Unknown | 2 | Unknown | Disseminated | ||
| Actinolite | Alteration | Unknown | 3 | Unknown | Disseminated | ||
| Biotite | Alteration | Unknown | 4 | Unknown | Disseminated |
Dec 07, 2005 (D McKay) - Wells (1984, assessment files) described the mineralization as follows: Mineralization occurs in both a quartz vein which strikes 260 degrees and dips 55 degrees N and an adjacent gossan zone (10 cm wide, 1-10% diss. py tr cp). Grab samples collected from the occurrence in 1983 by OGS Resident Geologist staff returned assay values which varied from <0.01 to 0.20 opt Au, <0.10 to 0.20 opt Ag and 126 to 166 ppm Cu. Wells (1984, assessment files) stated that a chip sample of the quartz vein assayed 26 ppb Au over 1.5 m (TBS 1463) whereas a chip sample of the host rock assayed 117 ppb Au, 75 ppm Cu, and 236 ppm Zn over 2.5 m (TBS 1464).
Dec 07, 2005 (D McKay) - Schnieders et al. (1996) state: The metavolcanic rocks are highly foliated, with foliation striking 58 degrees and display epidote, actinolite and biotite alteration.
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:
MonoMap - Mineral deposits of the Big Duck Lake area, District of Thunder Bay
Publication Number: R027 Page: 34-35 Date: 1997
Author: Pye E.G.
Publisher Name: Ontario Dept. of Mines
Location:
File - Schreiber-Hemlo Resident Geologist Mineral Deposit Files
Publication Number: Min Dep Date:
Author:
Publisher Name:
Location: Thunder Bay RGP
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:
Mono - Gold deposits of Ontario, part 1, districts of Algoma, Cochrane, Kenora, Rainy River, and Thunder Bay
Publication Number: MDC013 Page: 301 Date: 1971
Author: Ferguson S.A., Groen H.A., Haynes R.
Publisher Name: Ontario Dept. of Mines and Northern Affairs
Location:
Mono - Mineral Occurrences in the Nipigon-Marathon Area, Volumes 1 and 2.
Publication Number: OFR5951 Page: 826-828 Date: 1996
Author: Schnieders B.R., Smyk M.C., Speed A.A., McKay D.B.
Publisher Name: Ontario Geological Survey
Location:
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