Crustal contamination, sulphide mineralization, and compaction during formation of the marginal zone of the Muskox intrusion, Nunavut, and implications for the evolution of the 1.27 Ga Mackenzie magmatic event ...
The age, petrology, geochemistry, and Hf-Nd-S isotopic compositions of basal marginal rocks at two locations (West Pyrrhotite Lake and Far West Margin) along the western margin of the large Muskox layered mafic-ultramafic intrusion, Nunavut, are used (1) to constrain the petrogenesis of the marginal...
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| Format: | Text |
| Language: | English |
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University of British Columbia
2010
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| Online Access: | https://dx.doi.org/10.14288/1.0052551 https://doi.library.ubc.ca/10.14288/1.0052551 |
| Summary: | The age, petrology, geochemistry, and Hf-Nd-S isotopic compositions of basal marginal rocks at two locations (West Pyrrhotite Lake and Far West Margin) along the western margin of the large Muskox layered mafic-ultramafic intrusion, Nunavut, are used (1) to constrain the petrogenesis of the marginal zone and associated sulphide mineralization, and (2) to evaluate the genetic relationship of the Muskox intrusion with the Mackenzie dikes and Coppermine River flood basalts during the 1.27 Ga Mackenzie magmatic event. The marginal zone (1269 ± 2 Ma; U-Pb baddeleyite) consists of a lower 10 m-thick gabbronorite and upper 100-150 mthick peridotite subzone. A shift in incompatible trace element ratios and isotopic compositions at the transition from peridotite (low Th/Yb; high Nb/La; E[sub Hf(t)] = -3 to +2; E[sub Nd(t)]= -4 to 0; δ³⁴S = +6) to gabbronorite (E[sub Hf(t)] = -5 to -15; E[sub Nd(t)] = -1 to -13; δ³⁴S = +7 to +10) and the corresponding early crystallization of orthopyroxene and appearance of granophyre ... |
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