Ministry of Energy, Northern Development and Mines
Permanent Link to this Record: MDI000000000516Deposit Name(s) | Graff Lake Se - 1997, Ddh 549-004 - 1997 |
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Deposit Status | occurrence |
Date Created | 2008-Mar-18 |
Date Last Modified | 2019-Sep-12 |
Created By | M A Puumala |
Revised By | T Pettigrew |
Primary Commodities: gold
Township or Area: Zeemel Lake Area
Latitude: 52° 33' 44.89" Longitude: -90° 15' 5.05"
UTM Zone: 15 Easting: 686300 Northing: 5827150 UTM Datum: NAD83
Resident Geologist District: Thunder Bay North
NTS Grid: 53B09SW
Point Location Description: ddh database
Location Method: data compilation
1981-82: Geological and geophysical surveys by Canadian Nickel Company. 1985-1988: Geological and geophysical surveys and diamond drilling by Power Explorations Inc. 1996-97: Placer Dome conducted a ground magnetometer survey and drilled 5 DDH totalling 1033.75 m in the area, including 1 DDH totalling 253 m on the occurrence.
Office File Number | Online Assessment File Identifier | Online Assessment File Directory |
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2.11892 | 53B09SW0002 | Open |
2.5417 | 53B09SW9413 | Open |
2.17312 | 53B09SE0012 | Open |
53B09SW0037 | 53B09SW0011 | Open Open |
2.17166 | 53B09SE0010 | Open |
Province: Superior
Subprovince: Sachigo
Belt: North Caribou
Terrane: North Caribou
Geological Age: Mesoarchean
Tectonic Assemblage: McGruer - Opapimiskan Unit
Structure Name | Scale | Strike | Dip | Trend | Plunge |
---|---|---|---|---|---|
Fold Axis | local | 300 | 20 | ||
Foliation | regional | 300 |
Rock Type | Rank | Composition | Texture | Relationship |
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mafic metavolcanics | 1 | contains | ||
iron formation | 2 | contains | ||
metasedimentary | 3 | near |
Rank | Mineral Name | Class | Economic Mineral Type | Alteration Mineral Type | Alteration Ranking | Alteration Intensity | Habit Description |
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1 | pyrrhotite | economic | ore | ||||
carbonate | alteration | carbonatization | 1 | unknown | disseminated | ||
silica | alteration | silicification | 2 | unknown | disseminated |
03/18/2008 (M A Puumala) - This occurrence is based on anomalous gold assay results reported from Placer Dome diamond drill hole 549-004 (AFRI# 53B09SE0010). The most significant assay reported from this drill hole was 1.53 g/t Au over 0.5 m (31.75 to 32.25 m) in foliated mafic flows containing patchy silicification and carbonatization, and mineralized with 1.5% pyrrhotite. A second occurrence-grade assay of 0.55 g/t Au was reported from a 1 m (116.03 to 117.03 m) intersection of oxide facies iron formation mineralized with 3% pyrrhotite. The host mafic metavolcanic rocks are part of the Opapimiskan unit of the McGruer assemblage (Thurston, Osmani and Stone 1991). This metavolcanic rock assemblage is approximately 650 m wide in this area, and is dominated by fine to medium grained mafic to ultramafic metavolcanics. The metavolcanics are interbedded with several bands of chert and oxide facies iron formation. Metasedimentary rocks of the Zeemel-Heaton assemblage (Thurston, Osmani and Stone 1991) are present to the north and south of the metavolcanics. The drill hole log for KZ-87-1 indicates that the mafic metavolcanics in this area are interbedded with clastic metasediments (wacke), with an increasing proportion of wacke toward the bottom (southwest end) of the hole. This suggests that this occurrence is located adjacent to the southern margin of the metavolcanic assemblage. Mapping by Huston (1988) indicates that bedding and foliation in the area of this occurrence are generally subparallel, striking approximately 300 with near-vertical dip. Huston (1988) also reports the presence of folds with axes that consistently plunge 18 to 20 degrees to the northwest. Shearing is also reported to be common in the metavolcanics and banded iron formation/chert units, with shearing planes generally subparallel to the regional foliation and fold axes.
Rank | Classification |
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1 | lode (gold) |
Rank | Characteristic |
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1 | sheared |
Book - Northwestern Superior Province: Review and Terrane Analysis, in Geology of Ontario; Ontario Geological Survey, Special Volume 4, Part 1, p. 81-142.
Publication Number: SV04-01 Date: 1991
Author: Thurston, P.C., Osmani, I.A. and Stone, D.
Publisher Name: OGS
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