Ancient roots of tungsten in western North America

Abstract The highly irregular and localized distribution of tungsten deposits worldwide constitutes a supply challenge for basic industries such as steel carbides. Over Earth's history, has preferentially accumulated at paleocontinental margins formed during the breakup supercontinents. Later crustal thickening these paleogeographic regions magmas they produce are associated with large districts. However, all largest in modern North American Cordillera, which preserves over 3 b.y. geologic record margin abundant magmatism, limited to narrow Canadian Tungsten Belt northwestern Canada. We use neodymium isotopic compositions scheelite (CaWO4) from Cordillera constrain factors that control distribution. document is specifically materials that, on average, were derived mantle Mesoarchean Paleoproterozoic. Weathering erosion supercontinents Columbia Rodinia favored pre-enrichment sediments. orogenic heating pre-enriched sediments produced reduced melts capable efficiently scavenging America.