The source of tungsten-associated magmas in the northern Canadian Cordillera and implications for the basement

Abstract The crustally derived Tungsten Plutonic Suite (TPS) in the northern Canadian Cordillera is responsible for several of world’s most important tungsten (W) resources, but actual source rocks to these exceptionally metallogenic magmas have never been identified. Detrital zircon studies improved our knowledge exposed supracrustal packages region, such that a U-Pb study inherited cores TPS provides an opportunity determine age and provenance melt magmas. dominated by Neoarchean Paleoproterozoic zircons are typical northwest Laurentian “cratonic” detrital signature (e.g., 2.8–1.8 Ga). Cross-correlation statistical analysis populations combined with whole-rock neodymium isotopic compositions indicate mid- late Cambrian sedimentary Selwyn Basin likely Despite presence prospective intrusions across Basin, world-class W metallogeny limited narrow belt plutons eastern near ancient continental margin, possibly due depositional or structural controls on strata. Today, early Phanerozoic must be present at depths least 15–17 km notably younger than suggested current geophysical interpretations middle crust, requiring reconsideration crustal architecture Cordillera.