Timing of high-pressure metamorphism in the Yukon – Tanana terrane, Canadian Cordillera: constraints from U – Pb zircon dating of eclogite from the Teslin tectonic zone
- 1 May 1997
- journal article
- research article
- Published by Canadian Science Publishing in Canadian Journal of Earth Sciences
- Vol. 34 (5) , 709-715
- https://doi.org/10.1139/e17-057
Abstract
Zircon from eclogite near Last Peak in the Teslin tectonic zone yielded a U–Pb isotopic age of 269 + 2 Ma (2σ), the first precise age for such a rock in the Yukon –Tanana terrane of the Canadian Cordillera. Both the morphology and geochemistry of the eclogitic zircons indicate a metamorphic origin, and the U – Pb age therefore constrains the timing of peak high-pressure metamorphism in this rock. The U – Pb age demonstrates for the first time that an Early Permian high-pressure metamorphic event occurred in rocks now making up the Teslin tectonic zone, and possibly elsewhere in the Yukon – Tanana terrane. This U – Pb age provides a new geochronologic "pin" in the evolution of the Yukon – Tanana terrane prior to its Mesozoic accretion to the North American continental margin and, combined with recent 40Ar/39Ar muscovite data, indicates that high-pressure metamorphism at this time was a relatively short-lived event.Keywords
This publication has 29 references indexed in Scilit:
- Morphology versus UPb systematics in zircon: a high-resolution isotopic study of a zircon population from a Variscan dike in the Central AlpsPublished by Elsevier ,2002
- Tectonic and metamorphic events in the westernmost Grenville Province, central Ontario: new results from high-precision U–Pb zircon geochronologyCanadian Journal of Earth Sciences, 1995
- High-pressure amphibolite facies dynamic metamorphism and the Mesozoic tectonic evolution of an ancient continental margin, east-central AlaskaJournal of Metamorphic Geology, 1995
- Age and nature of protoliths in the Caledonian blueschist-eclogite complex of western Spitsbergen: a combined approach using UPb, SmNd and REE whole-rock systemsLithos, 1993
- Eclogitic rocks in the St. Cyr klippe, Yukon, and their tectonic significanceCanadian Journal of Earth Sciences, 1992
- Isotopic (RbSr, UPb and SmNd) and trace element geochemistry of eclogites from the pan-African Belt: A case study of REE fractionation during high-grade metamorphismLithos, 1991
- Blueschist and eclogite in mylonitic allochthons, Ross River and Watson Lake areas, southeastern YukonCanadian Journal of Earth Sciences, 1987
- An examination of the cataclastic fabrics and structures of parts of Nisutlin, Anvil and Simpson allochthons, central Yukon: test of the arc-continent collision modelJournal of Structural Geology, 1985
- Eclogite from central Yukon: a record of subduction at the western margin of ancient North AmericaCanadian Journal of Earth Sciences, 1983
- Mass spectrometry of nanogram-size samples of leadAnalytical Chemistry, 1969