| Title | Lac Soisson Intrusive Suite: a potential extension of the Nain Plutonic Complex in the western Core Zone, Quebec |
| Download | Downloads |
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| Licence | Please note the adoption of the Open Government Licence - Canada
supersedes any previous licences. |
| Author | Corrigan, D ;
Wodicka, N; Lafrance, I; Bandyayera, D |
| Source | Geological Survey of Canada, Scientific Presentation 99, 2019, 1 sheet, https://doi.org/10.4095/314596  Open Access |
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| Year | 2019 |
| Publisher | Natural Resources Canada |
| Document | serial |
| Lang. | English; French |
| Media | on-line; digital |
| File format | pdf (Adobe® Reader®) |
| Province | Quebec |
| NTS | 24G |
| Area | Nunavik; Lac Saffray; Lac La Moinerie; Rivière à la Baleine |
| Lat/Long WENS | -68.0000 -66.0000 58.0000 57.0000 |
| Subjects | economic geology; regional geology; stratigraphy; structural geology; geochronology; tectonics; geophysics; mineral deposits; mineral exploration; nickel; copper; mineralization; tectonic history;
emplacement; intrusions; plutons; dykes; crystallization; bedrock geology; lithology; intrusive rocks; mafic intrusive rocks; gabbros; troctolites; migmatites; metatexites; diatexites; metamorphic rocks; structural features; faults; lineaments; shear
zones; radiometric dating; uranium lead dating; lead lead dates; mass spectrometer analysis; correlations; geophysical surveys; aeromagnetic surveys; magnetic interpretations; Archean; Core Zone; Lac Soisson Intrusive Suite; Nain Plutonic Suite;
Rivière George Shear Zone; Rivière Marralik Shear Zone; Lac Pingiajjulik Fault; Winnie Suite; Qurlutuq Complex; Rivière False Suite; Mesoproterozoic; platinum group elements; Precambrian; Proterozoic |
| Illustrations | geoscientific sketch maps; photomicrographs; photographs; Concordia diagrams |
| Program | GEM2: Geo-mapping for Energy and Minerals Hudson/Ungava Core Zone |
| Program | Polar Continental Shelf Program
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| Released | 2019 04 23 |
| Abstract | The Lac Soisson intrusive suite consists of a swarm of small plutons and plugs of olivine-gabbro, gabbronorite and troctolite composition that were emplaced into Archean to Paleoproterozoic crust of the
western Core Zone, west of the de Pas Batholith. These intrusions are essentially non-metamorphosed, with unaltered olivine visible in hand specimen and thin section. They were mapped in detail by the Ministère de l'Énergie et des Ressources
naturelles (MERN) in 2013 as part of the Lac Saffray mapping project in the Core Zone, and revisited this past summer where a B.Sc. Honours thesis was initiated (Fleury, 2016), supported by the MERN. In 2000-2002, these intrusions had been targeted
by the Western Mining Corporation (WMC) as part of their 'Quebec-7' Ni-Cu-PGE exploration program along the western margin of the SE Churchill Province. Some of the values reported by WMC range up to 2% chalcopyrite, < 2% pentlandite and 108 ppb PGEs
over meter-length sections in drillcore. During our targeted mapping in 2014 we sampled one of the main gabbroic phases of the intrusion for U-Pb dating. The sample yielded abundant, large baddeleyite and zircon crystals, which were analyzed at the
Geological Survey of Canada laboratory in Ottawa. Preliminary TIMS results stemming from the baddeleyite ages suggest that the magma was emplaced at 1312 ±1 Ma, slightly younger than the ca. 1333 ± 1 Ma Ni-bearing intrusions of the Voisey's Bay
complex in Nain. Zircon from the same Lac Soisson sample, however, yields a younger SHRIMP concordia age of 1295 ±11 Ma. Interestingly, some of the Voisey's Bay zircons yield ages that are compatible with baddeleyite ages (1333 Ma), whereas others
yield ages that are significantly younger, at ca. 1305 Ma. During the summer 2014, east-west oriented olivine gabbro dykes were also mapped and sampled as part of the regional mapping program. These E-W dykes are parallel to a set of crustal-scale
faults and lineaments that appear to be associated to crustal extension related to emplacement of the Nain Plutonic Suite. Some may in turn be feeders to the Lac Soisson intrusions. However, preliminary TIMS results suggest an age of ca. 1270 Ma for
one of these dykes. The age correlation shown herein suggests that Ni-Cu mineralized, olivine-bearing mafic intrusions of the Soisson Suite may very likely be related to the Voisey's Bay intrusions but were emplaced more than 300 km to the W-NW of
the latter, in the western margin of the Core Zone. |
| Summary | (Plain Language Summary, not published)
This poster, presented at the Géologie Quebec conference in November 2015, provides details of a new U-Pb age obtained on a norite from the Lac Soisson
intrusive complex, which now makes it part of the Nain Plutonic suite. This means that potential for Voisey's Bay Ni-Cu-PGE mineralization may extend as far as 300km further west of presently known occurrences. |
| GEOSCAN ID | 314596 |
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