| Title | Volcanology, geochemistry and petrogenesis of the Expo-Raglan magmatic system in the eastern Cape Smith Belt, Nunavik, northern Quebec |
| Download | Download (whole publication) |
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| Licence | Please note the adoption of the Open Government Licence - Canada
supersedes any previous licences. |
| Author | McKevitt, D J; Lesher, C M; Houlé, M G |
| Source | Targeted Geoscience Initiative: 2018 report of activities; by Rogers, N (ed.); Geological Survey of Canada, Open File 8549, 2019 p. 393-401, https://doi.org/10.4095/313674  Open Access |
| Year | 2019 |
| Publisher | Natural Resources Canada |
| Document | open file |
| Lang. | English |
| Media | on-line; digital |
| Related | This publication is contained in Targeted Geoscience
Initiative: 2018 report of activities |
| File format | pdf |
| Province | Quebec |
| NTS | 35G/08; 35G/09; 35G/16; 35H/05; 35H/11; 35H/12; 35H/13; 35H/14 |
| Area | Nunavik; Lac Vaillant; Lac Rinfret; Lac Cross |
| Lat/Long WENS | -74.5000 -73.0000 61.8000 61.4000 |
| Subjects | economic geology; tectonics; geochemistry; mineral deposits; mineral exploration; mineral potential; nickel; copper; sulphide deposits; ore mineral genesis; mineralization; ore controls; petrogenesis;
tectonic setting; volcanology; volcanic-sedimentary belts; magmatism; intrusions; dykes; sills; volcanism; fluid dynamics; fluid flow; plate margins; bedrock geology; lithology; igneous rocks; intrusive rocks; volcanic rocks; mafic rocks; ultramafic
rocks; petrographic analyses; thin section microscopy; geochemical analyses; field work; Cape Smith Belt; Southern Domain; Chukotat Group; Esker Lake Group; Povungnituk Group; Nuvilic Formation; Cécilia Formation; Beauparlant Formation; Nituk
Formation; Kuuvvaluk Formation; Bélanger Gabbroic Suite; Expo Trend; Raglan Trend; Expo Dykes; Churchill Province; Paleoproterozoic; Precambrian; Proterozoic |
| Illustrations | location maps; geoscientific sketch maps; geochemical plots; photographs; schematic models |
| Program | Targeted Geoscience Initiative (TGI-5) Knowledge Management Coordination |
| Program | Targeted Geoscience Initiative (TGI-5) Nickel-copper-PGE-chromium ore systems - deposit controls in cratonic areas |
| Released | 2019 03 01 |
| Abstract | The Paleoproterozoic volcano-sedimentary Cape Smith Belt in Nunavik (northern Quebec) contains a variety of mafic-ultramafic units classifiable by position in sequence, geometry, lithology, degree of
differentiation and mineralization style. Non-differentiated to differentiated mafic flows/sills comprise the majority of the section as essentially non-mineralized massive-pillowed basalts, conformable gabbroic units and differentiated
pyroxenite/gabbro/basalt flows. Differentiated mafic-ultramafic sills intrude sedimentary strata of the lower and upper Povungnituk Group and host reef-style PGE-(Cu)-(Ni) mineralization (e.g. Delta). Poorly differentiated ultramafic-mafic bladed
dykes along the Expo Trend in the Povungnituk Group commonly host Cu-Ni-(PGE) sulphides along their margins (e.g. Expo-Ungava, Méquillon) and reach up to 35 weight % MgO in the most magnesian olivine pyroxenitic parts and up to 16 weight % MgO in
their chilled melanogabbroic margins. Poorly differentiated ultramafic lava channels along the Raglan Trend at the base of the Chukotat Group host Ni-Cu-(PGE) mineralization at or near their lower contacts, and reach MgO contents of nearly 44 weight
% in the most magnesian peridotitic parts and up to 20 weight % in their chilled pyroxenitic margins. Recent dating indicates a temporal overlap between the Expo and Raglan parts of the system; however, field and geochemical data suggest that the
Expo dykes are derived from less magnesian magmas and formed mineralization with higher Cu/Ni ratios than the lava channels in in the Raglan Trend. The Expo dykes may have fed other parts of the system, but do not appear to represent direct feeders
to the mineralized lava channels in the Raglan parts. |
| Summary | (Plain Language Summary, not published)
The Targeted Geoscience Initiative (TGI) is directed towards providing next generation knowledge and methods to facilitate more effective targeting of
buried mineral deposits. The program aims to enhance the effectiveness of exploration for Canada's major mineral systems by resolving foundational geoscience problems that constrain the geological processes responsible for the liberation metals from
their source region, transportation of these ore metals and control their eventual deposition. TGI supports projects on gold, Ni-Cr-PGE, porphyry-style mineralization, uranium and volcanic- and sedimentary-hosted base metal mineralization ore
systems, with each project divided into subprojects focused on resolving specific knowledge gaps by integrating data and studies from multiple sites across Canada. Herein, we present interim results and interpretations from a selection of the
research activities currently being conducted under the auspices of TGI. |
| GEOSCAN ID | 313674 |
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