Major and trace element compositions and Sr-Nd-Pb systematics of crystalline rocks from the Dawson Range, Yukon, Canada

• Published in: Canadian Journal of Earth Sciences
• Main Authors: Selby, David, Creaser, Robert A, Nesbitt, Bruce E
• Format: Article in Journal/Newspaper
• Language: English
• Published: Canadian Science Publishing 1999
• Subjects: Canada; Dawson Range; Yukon; Dawson
• Online Access: http://dx.doi.org/10.1139/e99-058; http://www.nrcresearchpress.com/doi/pdf/10.1139/e99-058

Geochemical (major, trace, and rare earth elements) and isotopic (Nd, Sr, and Pb) data of the Devono-Mississippian Wolverine Creek Metamorphic Suite, mid-Cretaceous Dawson Range batholith, mid-Cretaceous Casino Plutonic Suite, and Late Cretaceous plutons provide new information on the origin and evolution of the rocks from the Dawson Range in west-central Yukon, northern Canadian Cordillera. Isotopic and other geochemical data for the Wolverine Creek Metamorphic Suite metasedimentary rocks indicate that the detrital components were derived from two distinct provenances: (1) the North America craton, which contributed evolved felsic, upper crustal material; and (2) a calc-alkaline arc, which shed juvenile mafic-intermediate material. The geochemical affinity of the metaigneous rocks indicates that the Yukon-Tanana terrane represented a continental arc during Devonian-Mississippian times, with magmas derived from geochemically primitive sources and partial melting of the Yukon-Tanana terrane supracrustal rocks. The Dawson Range batholith likely represents crustally derived magmas from the Yukon-Tanana terrane during the mid-Cretaceous, with the contemporaneous Casino Plutonic Suite representing a late-stage fractionate of these magmas. The Late Cretaceous porphyry Cu mineralization is genetically related to plutons derived from mantle-source magmas related to active subduction.