scholarly journals Contact-style magmatic sulphide mineralisation in the Labrador Trough, northern Quebec, Canada: implications for regional prospectivity

2020 ◽  
Vol 57 (7) ◽  
pp. 867-883 ◽  
Author(s):  
W.D. Smith ◽  
W.D. Maier ◽  
I. Bliss
Keyword(s):  
Platinum Group Element ◽  
Group Element ◽  
Common Source ◽  
Upper Crust ◽  
Sulphide Ores ◽  
Sulphide Mineralisation ◽  
Platinum Group ◽  
R Factors ◽  
Pge Geochemistry

The Labrador Trough in northern Quebec is currently the focus of ongoing exploration for magmatic Ni-Cu-platinum group element (PGE) sulphide ores. This geological belt hosts voluminous basaltic sills and lavas of the Montagnais Sill Complex, which are locally emplaced among sulphidic metasedimentary country rocks. The recently discovered Idefix PGE-Cu prospect represents a stack of gabbroic sills that host stratiform patchy disseminated to net-textured sulphides (0.2–0.4 g/t PGE+Au) over a thickness of ∼20 m, for up to 7 km. In addition, globular sulphides occur at the base of the sill, adjacent to the metasedimentary floor rocks. Whole-rock and PGE geochemistry indicates that the sills share a common source and that the extracted magma underwent significant fractionation before emplacement in the upper crust. To develop the PGE-enriched ores, sulphide melt saturation was attained before final emplacement, peaking at R factors of ∼10 000. Globular sulphides entrained along the base of the sill ingested crustally derived arsenic and were ultimately preserved in the advancing chilled margin.

Platinum-group element (PGE) geochemistry of the Emeishan basalts in the Pan-Xi area, SW China

2006 ◽  
Vol 51 (7) ◽  
pp. 845-854 ◽  
Author(s):  
Hong Zhong ◽  
Weiguang Zhu ◽  
Liang Qi ◽  
Meifu Zhou ◽  
Xieyan Song ◽  
...  
Keyword(s):  
Platinum Group Element ◽  
Group Element ◽  
Sw China ◽  
Platinum Group ◽  
Pge Geochemistry

Platinum-group element (PGE) geochemistry of Mesoarchean ultramafic–mafic cumulate rocks and chromitites from the Nuasahi Massif, Singhbhum Craton (India)

Lithos ◽  
2014 ◽  
Vol 205 ◽  
pp. 322-340 ◽  
Author(s):  
Sarifa Khatun ◽  
Sisir K. Mondal ◽  
Mei-Fu Zhou ◽  
Vysetti Balaram ◽  
Hazel M. Prichard
Keyword(s):  
Platinum Group Element ◽  
Group Element ◽  
Singhbhum Craton ◽  
Platinum Group ◽  
Pge Geochemistry

On the Mechanisms for Low-Sulfide, High-Platinum Group Element and High-Sulfide, Low-Platinum Group Element Mineralization in the Eastern Gabbro, Coldwell Complex, Canada: Evidence from Textural Associations, S/Se Values, and Platinum Group Element Concentrations of Base Metal Sulfides

2020 ◽  
Vol 115 (2) ◽  
pp. 355-384
Author(s):  
M. J. Brzozowski ◽  
I. M. Samson ◽  
J. E. Gagnon ◽  
D. J. Good ◽  
R. L. Linnen
Keyword(s):  
Base Metal ◽  
Platinum Group Element ◽  
Metal Sulfide ◽  
Group Element ◽  
Pge Mineralization ◽  
Base Metal Sulfides ◽  
Wide Range ◽  
Platinum Group ◽  
Compositional Variations ◽  
R Factors

Abstract The Eastern Gabbro, Coldwell Complex, hosts several geochemically and mineralogically distinct Cu-platinum group element (PGE) deposits, including the high-grade W Horizon (>100 ppm Pd-Pt-Au over 2 m). Several magmatic and/or hydrothermal models have previously been proposed to explain the range of enrichment in PGEs observed in the Marathon deposit, but no work has integrated textural and compositional variations in sulfides to elucidate which of these models is most suitable. Additionally, comparatively little work has been done to characterize the genesis of Cu-PGE mineralization that occurs to the northwest of the Marathon deposit in the Eastern Gabbro. Through integration of base metal sulfide (BMS) mineralogy, texture, and trace element chemistry, a wide range of magmatic and postmagmatic processes have been characterized that contributed to the formation of these deposits. In all zones of mineralization in the Eastern Gabbro, chalcophile elements were remobilized from primary chalcopyrite by hydrothermal fluids and precipitated as secondary chalcopyrite, which occurs as a replacement of pyrrhotite and as intergrowths with hydrous silicates. BMSs in the mineralized zones in the Marathon deposit (Footwall zone, Main zone, and W Horizon) experienced higher R factors than those deposits located northwest of the Marathon deposit (Four Dams, Area 41, and Redstone), with BMSs in the W Horizon having experienced the highest R factors. The silicate melts from which the Footwall zone crystallized likely experienced some degree of sulfide segregation at depth, albeit to a much lesser degree than the northern deposits. Additionally, the melts from which the mineralized zones in the Marathon deposit crystallized were likely contaminated by high-S/Se Archean sedimentary rocks, whereas the northern deposits were likely contaminated by low-S/Se igneous and/or metamorphic rocks. BMSs in a chalcopyrite-rich pod located within the vicinity of the Coldwell Complex experienced both high R factors and high degrees of contamination (cf. W Horizon and Footwall zone, respectively). This study illustrates the complexity of processes that generate and modify mineralization in conduit-type Ni-Cu-PGE systems.

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