Detrital zircon U-Pb and Hf isotope signature of Carboniferous and older strata of the Yukon-Tanana terrane in Yukon, Canadian Cordillera: Implications for terrane correlations and the onset of Late Devonian arc magmatism

The Yukon-Tanana terrane in Yukon, Canada, records Late Devonian (ca. 366–360 Ma) rifting and the onset of latest Devonian–Carboniferous arc back-arc magmatism 360–325 Northern Cordillera. Detrital zircon U-Pb Hf isotope analyses indicate that metasedimentary basement was sourced northwestern Laurentia. Sandstones successions generally have robust Devonian–Mississippian age peaks, their signatures are characterized by strongly negative εHft values zircons followed progressively more juvenile Carboniferous zircons. This isotopic “pull-up” reflects melting Precambrian crust related to regional extension Devonian, as matured through Carboniferous. Paleozoic rocks Tracy Arm southeastern Alaska, USA (formerly south), been compared with Yukon. from distinct populations sources along a different segment Laurentian margin terrane. Magmatism ranges 440 Ma 360 is an “pull-down” Silurian Early Middle second early Mississippian. Thus, terranes record pre-Carboniferous histories. Interactions between these two suggested influx exotic Mississippian clasts detrital on match