| Title | The Ferguson Lake deposit: an example of Ni-Cu-Co-PGE mineralization in a back-arc basin setting? |
| Author | Acosta-Góngora, P; Pehrsson, S J; Sandeman, H; Martel, E; Peterson, T |
| Source | Canadian Journal of Earth Sciences vol. 55, no. 8, 2018 p. 958-979, https://doi.org/10.1139/cjes-2017-0185 (Open Access) |
| Year | 2018 |
| Alt Series | Natural Resources Canada, Contribution Series 20170289 |
| Publisher | Canadian Science Publishing |
| Document | serial |
| Lang. | English |
| Media | paper; on-line; digital |
| File format | pdf (Adobe® Reader®); html; tif |
| Province | Nunavut |
| NTS | 65I/09; 65I/10; 65I/11; 65I/14; 65I/15; 65I/16 |
| Area | Ferguson Lake |
| Lat/Long WENS | -97.5000 -96.0000 63.0000 62.5000 |
| Subjects | economic geology; tectonics; geochemistry; mineral deposits; mineral potential; nickel; copper; cobalt; sulphide deposits; mineralization; mineral exploration; exploration guidelines; tectonic setting;
geodynamics; mid-ocean ridges; basins; greenstone belts; metamorphism; intrusions; metamorphic facies; amphibolite facies; whole rock geochemistry; trace element analyses; major element analyses; geochemical anomalies; niobium geochemistry; ytterbium
geochemistry; thorium geochemistry; zirconium geochemistry; magnesium geochemistry; metasomatism; bedrock geology; lithology; ultramafic rocks; igneous rocks; intrusive rocks; tonalites; granodiorites; granites; diorites; monzo-granites; syenites;
gabbros; hornblendites; volcanic rocks; volcaniclastics; basalts; metamorphic rocks; metavolcanic rocks; metasedimentary rocks; psammites; structural features; faults; antiforms; synforms; shear zones; faults; petrographic analyses; petrogenesis;
Archean; Ferguson Lake Deposit; Ferguson Lake Igneous Complex; Yathkyed Greenstone Belt; Chesterfield Block; Churchill Province; MacQuoid Greenstone Belt; Hearne Craton; Rae Craton; Hudson Granite; Suluk Occurrence; platinum group elements;
extension; back-arc basins; massive sulphide deposits; rare earth element analyses; mid-ocean ridge basalts (MORB); silicon dioxide; Precambrian; Proterozoic |
| Illustrations | location maps; geoscientific sketch maps; schematic representations; photographs; photomicrographs; tables; geochemical plots; ternary diagrams |
| Program | South Rae Province Bedrock/Surficial geology, GEM2: Geo-mapping for Energy and Minerals |
| Released | 2018 05 02 |
| Abstract | The world's largest Ni-Cu-Platinum group element (PGE) deposits are dominantly hosted by ultramafic rocks within continental extensional settings (e.g., Raglan, Voisey's Bay), resulting in a focus on
exploration in similar geodynamic settings. Consequently, the economic potential of other extensional tectonic environments, such as ocean ridges and back-arc basins, may be underestimated. In the northeastern portion of the ca. 2.7 Ga Yathkyed
greenstone belt of the Chesterfield block (western Churchill Province, Canada), the Ni-Cu-Co-PGE Ferguson Lake deposit is hosted by >2.6 Ga hornblenditic to gabbroic rocks of the Ferguson Lake Igneous Complex (FLIC), which is metamorphosed up to
amphibolitic facies. The FLIC has a basaltic composition (Mg# = 31-72), flat to slightly negatively sloped normalized trace element patterns (La/Yb(PM) = 0.7-3.5), and negative Zr, Ti, and Nb anomalies. The FLIC rocks are geochemically similar to the
2.7 Ga back-arc basin tholeiitic basalts from the adjacent Yathkyed and MacQuoid greenstone belts (Mg# = 30-67; La/Yb(PM) = 0.3-3.0), but the Ferguson Lake intrusions appear to be more crustally contaminated. We interpret the FLIC to have formed in
an equivalent back-arc basin setting. This geodynamic setting is rare for the formation of Ni-Cu-PGE occurrences, and only few examples of this tectonic environment (or variations of it, e.g., rifted back-arc) are found in other Proterozoic and
Archean sequences (e.g., Lorraine deposit, Quebec). We suggest that back-arc basin-derived mafic rocks within the Yathkyed and other Neoarchean greenstone belts of the Chesterfield block (MacQuoid and Angikuni) could represent important targets for
future mineral exploration. |
| Summary | (Plain Language Summary, not published)
This work documents the geochemical characteristics of the gabbroic intrusion host to the Ferguson Lake Ni-Cu-Co-PGE mineralization, in the Nunavut
Territory. This study suggests that the Ferguson lake was formed in a back-arc basin setting, similar to that of the neighboring 2.7 Ga Yathkyed and MacQuoid greenstone belts. The main implications are: 1) the occurrence of Ni-Cu-PGE mineralization
in a back-arc basin environment, which is rare in the geological record and 2) The potential for Ni-Cu-PGE mineralization in similar gabbroic rocks within the Yathkyed and MacQuoid belts. |
| GEOSCAN ID | 306293 |
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