U-Pb geochronology of deformation and metamorphism across a central transect of the early Proterozoic Torngat Orogen, North River map area, Labrador

J. M. Bertrand, J. C. Roddick, Martin Van Kranendonk, I. Ermanovics

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The Early Proterozoic Torngat Orogen resulted from the oblique collision of the Archean Nain and southeastern Rae provinces and evolved in four stages: (1) deposition of platformal supracrustal assemblages followed by subduction-related arc magmatism in the margin of the Rae Province; (I) crustal thickening and nappe tectonics; (II) sinistral transpression and formation of the Abloviak shear zone; (III) uplift on steeply dipping, east-verging mylonites along the eastern orogenic front. U-Pb geochronology on zircon and monazite from major rock units and syntectonic intrusions indicates that arc magmatism at ca. 1880 Ma was followed by 40 Ma. of deformation and high-grade metamorphism from ca. 1860 to 1820. Subsequent uplift and final cooling occurred ca. 1795-1770 Ma. Several ages of mineral growth that correspond to distinct structural and metamorphic events have been recognized. -from Authors

Original languageEnglish
Pages (from-to)1470-1489
Number of pages20
JournalCanadian Journal of Earth Sciences
Issue number7
Publication statusPublished - Jan 1 1993
Externally publishedYes


ASJC Scopus subject areas

  • Earth and Planetary Sciences(all)

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