Thermochronology of Early Jurassic exhumation of the Yukon-Tanana terrane, west-central Yukon | Posted on:2013-05-07 | Degree:M.Sc | Type:Thesis | University:University of Ottawa (Canada) | Candidate:Knight, Eleanor | Full Text:PDF | GTID:2450390008471155 | Subject:Geology | Abstract/Summary: | | This study utilised U-Pb geochronology, and 40Ar/ 39Ar and (U-Th)/He thermochronology 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 predominantly 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/39 Ar 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.;Keywords: Cordillera, Yukon-Tanana terrane, geochronology, thermochronology, Jurassic, exhumation, extension. | Keywords/Search Tags: | Yukon-tanana terrane, Thermochronology, Exhumation, Jurassic | | Related items |
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