Thermochronology of Early Jurassic Exhumation of the Yukon-Tanana Terrane, West-central Yukon

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Title: Thermochronology of Early Jurassic Exhumation of the Yukon-Tanana Terrane, West-central Yukon
Authors: Knight, Eleanor
Date: 2012
Abstract: This study utilised U-Pb geochronology, and 40Ar/39Ar and (U-Th)/He thermochro-nology to delineate arc magmatism, metamorphism, and exhumation of the pericratonic Yukon-Tanana terrane in the McQuesten map area of west-central Yukon, Canada. SHRIMP U-Pb ages delineate Mid to Late Paleozoic arc magmatism and fit key units into the regional lithotectonic framework of the terrane. The juxtaposition of unmetamorphosed and predomi-nantly undeformed Devono-Mississippian rocks in the northwest of the study area with polydeformed and up to amphibolite facies metamorphosed rocks in the southwest suggests a crustal-scale discontinuity, the Willow Lake fault, bounds the two domains. The asymmetric distribution of 40Ar/39Ar ages across the fault suggest it is extensional, and was active in the Early Jurassic. Zircon (U-Th)/He ages delineate erosion of rocks in the northwest through the upper crust during the Late Triassic and Late Jurassic to Early Cretaceous followed by Mid-dle Cretaceous erosion of the southwestern domain and possibly fault reactivation.
URL: http://hdl.handle.net/10393/22933
http://dx.doi.org/10.20381/ruor-5866
CollectionThèses, 2011 - // Theses, 2011 -
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