캐나다
New geochronological and geochemical data for Permian rocks of the western Yukon-Tanana terrane, Klondike district, Yukon
New U-Pb zircon dates from Permian rocks of the Yukon-Tanana terrane in the Klondike district of western Yukon provide new constraints on timing of intrusions and deposition. The new data shows that significant Pb-loss affected zircon in metamorphic rocks of the Yukon-Tanana terrane. The new, high-precision CA-TIMS dating shows that all intrusions in the region are ca. 261 Ma and eliminate previous constraints on the Klondike orogeny. A review of lithogeochemical data and new Lu-Hf isotope data for zircon support development of the Klondike assemblage in back-arc to continental arc settings. New 40Ar/39Ar data for Permian metaplutonic rocks indicates cooling below 300-350°C in the Early Jurassic.