Ontario Geological Survey
Permanent Link to this Record:
MDI52I08NW00020
| Record Name(s) | Dempster East Dike - 1958 |
|---|---|
| Related Record Type | Partial |
| Related Record(s) | |
| Record Status | Occurrence |
| Date Created | 1983-Jan-12 |
| Date Last Modified | 2023-May-11 |
| Created By | |
| Revised By |
Primary Commodities: Lithium, Tantalum, Rubidium, Beryllium
Secondary Commodities: Cesium, Gallium, Niobium
Township or Area: Crescent Lake Area
Latitude: 50° 27' 41.68" Longitude: -88° 16' 9.75"
UTM Zone: 16 Easting: 409903 Northing: 5590723 UTM Datum: NAD83
Resident Geologist District: Thunder Bay North
NTS Grid: 52I08NW
Point Location Description: Sample H181051 location from Assessment file 20000005574
Location Method: Data Compilation
Access Description: Main access to the site is achieved via the North Jackfish Road, which is an extension of Airport Road, leading NE out of Armstrong. The roads leading onto the property are logging roads. The North Road separates from the main Jackfish Road at approximately the 76 km marker. There is an old road at the 5 km marker along the North Road that can be used to access the Dempster East showing. This trail was limited to ATV use only.
1959: Dempster Explorations Limited carried out channel sampling, assays. 1979: E. and B Explorations Inc. / Cominco Ltd. conducted mapping, geochemistry. 1982: Bird River Mines Company Ltd. carried out channel sampling. 2009-10: Canadian Orebodies conducted mapping, trenching and sampling.
| Office File Number | Online Assessment File Identifier | Online Assessment File Directory |
|---|---|---|
| 2.3207 | 52I08NE0006 | 52I08NE0006 |
| 2.3957 | 52I08NE0007 | 52I08NE0007 |
| 2.46173 | 20000005574 | 20000005574 |
Province: Superior
Subprovince: Wabigoon
Belt: Caribou Lake
Geological Age: Archean
| Rock Type | Rank | Composition | Texture | Relationship | Mafic lava flow-unsubdivided | 1 | Adjacent |
|---|---|---|---|---|
| Pegmatite | 2 | Is |
Mar 07, 2014 (A Wilson) - The deposit is a dike which cuts obliquely across the metavolcanics and has been traced in a general northwest direction for about 150 feet. Throughout much of its length it strikes N45W and is exposed across widths of 5 to 10 feet. To the southeast, however, it curves to strike S15E for about 35 feet, and here it is exposed across widths up to 15 feet. The dip of the deposit is not known.
| Rank | Mineral Name | Class | Economic Mineral Type | Alteration Mineral Type | Alteration Ranking | Alteration Intensity | Alteration Style |
|---|---|---|---|---|---|---|---|
| 1 | Spodumene | Economic | Ore | ||||
| 2 | Feldspar | Economic | Gangue | ||||
| 3 | Quartz | Economic | Gangue | ||||
| 4 | Albite | Economic | Gangue | ||||
| 5 | Muscovite | Economic | Gangue | ||||
| 6 | Apatite | Economic | Gangue | ||||
| 7 | Tourmaline | Economic | Gangue |
Mar 07, 2014 (A Wilson) - The pegmatite is made up of abundant medium-grained to coarse-grained potash feldspar and fine-grained prismatic spodumene associated with quartz, albite, muscovite, and accessory blue apatite as before; in a few places a little tourmaline is conspicuous because of its black colour. An interesting feature of the deposit is the fact that the spodumene crystals in places are oriented with their long dimensions parallel to the strike (N60E) of the host rocks. Some small inclusions of amphibolite are similarly oriented. These are sharply defined from the pegmatite along their sides, but they do show partial replacement by granular-textured muscovite, and they commonly finger out and grade lengthwise into the pegmatite. Six channel samples were cut with an average grade of 1.88% Li20. Three samples, cut from near the southeast end of the deposit, averaged 1.78% Li20 across a width of 13.5 feet.
Apr 10, 2019 (Therese Pettigrew) - A grab sample collected by Canadian Orebodies in 2009 returned an assay of 2.56% Li2O. Most of the samples were slightly to moderately enriched in beryllium, cesium, gallium, niobium, rubidium, tin and tantalum. Grab sample assays returned 66.8 ppm to 172 ppm Be, 0.14% to 0.38% Rb, 213 to 980 ppm Cs, 66.8 ppm to 93.1 ppm Ga, 58.4 to 140 ppm Ta, and 57.2 ppm to 90.1 ppm Nb (Assessment file 20000005574).
| Rank | Classification |
|---|---|
| 1 | Pegmatite |
Mono - Industrial minerals of northern Ontario-supplement 1
Publication Number: OFR5388 Page: 187-191 Date: 1982
Author: Vos M.A., Abolins T., Smith V.
Publisher Name: Ontario Geological Survey
Location:
MonoMap - Geology of the Crescent Lake area, District of Thunder Bay
Publication Number: R055 Page: 58 Date: 1968
Author: Pye E.G.
Publisher Name: Ontario Dept. of Mines
Location:
Mono - Pegmatite mineral resources of Ontario
Publication Number: IMR021 Page: 48 Date: 1997
Author: Hewitt D.F.
Publisher Name: Ontario Dept. of Mines
Location:
Map - Crescent Lake area, Thunder Bay District
Publication Number: M2100 Date: 1997
Author: Pye E.G.
Publisher Name: Ontario Dept. of Mines
Location:
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