| Title | Canadian shield / Bouclier canadien |
| Download | Downloads |
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| Licence | Please note the adoption of the Open Government Licence - Canada
supersedes any previous licences. |
| Author | Geological Survey of Canada |
| Source | Geological Survey of Canada, Current Research no. 1997-C, 1997, 254 pages, https://doi.org/10.4095/208626  Open Access |
| Image |  |
| Year | 1997 |
| Publisher | Natural Resources Canada |
| Document | serial |
| Lang. | English; French |
| Media | paper; on-line; digital |
| Related | This publication contains the following
publications |
| File format | pdf |
| Subjects | economic geology; geochemistry; geochronology; metallic minerals; stratigraphy; geophysics; igneous and metamorphic petrology; surficial geology/geomorphology; structural geology; lithology; mineral
deposits; metamorphism; metamorphic rocks; plutonic rocks; volcanic rocks; igneous rocks; sedimentary rocks; geophysical surveys; structural features; mineralization; stratigraphic analyses; metallogeny; radiometric dates; glacial deposits;
geochemical surveys; Canadian Shield; Precambrian |
| Released | 1997 02 01; 2013 04 30 |
| Abstract | Two magnetite-rich deposits at Tommie Lake are hosted by an east-trending, steeply dipping assemblage of rhyolite ignimbrite, tuff, and porphyritic dacite that underlies this region in the north-central
part of the continental, ca. 1860 Ma old Great Bear magmatic zone. One of the deposits is stratiform in a tuffaceous horizon, and contains disseminated pyrite and chalcopyrite in magnetite layers. The other, located 1 km to the south, is vein type.
The veins contain variable amounts of quartz, magnetite, pyrite, and chalcopyrite, and locally calcite and fluorite. Notable amounts of gold and tungsten occur in chalcopyi-iterich veins.
The deposits attest to an initial synvolcanic stratiform
concentration of the metals, and later hydrothermal activity related to granitic plutonism that remobilized and/or added various elements. The hydrothermal mineralization is akin to polymetallic magnetite-rich mineralization elsewhere in the magmatic
zone regarded as Kiruna/Olympic Dam type. |
| GEOSCAN ID | 208626 |
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