Polymetamorphic Evolution of the Trans-Hudson Orogen, Baffin Island, Canada: Integration of Petrological, Structural and Geochronological Data
Supracrustal units metamorphosed at mid-crustal conditions within the Paleoproterozoic Trans-Hudson Orogen are preserved within an obliquely exposed continental collision zone on Baffin Island (Canada). Early granulite-facies assemblages yield thermobarometric data and phase diagram information that...
| Published in: | Journal of Petrology |
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| Main Authors: | , , |
| Format: | Text |
| Language: | English |
| Published: |
Oxford University Press
2006
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| Subjects: | |
| Online Access: | http://petrology.oxfordjournals.org/cgi/content/short/egl060v1 https://doi.org/10.1093/petrology/egl060 |
| Summary: | Supracrustal units metamorphosed at mid-crustal conditions within the Paleoproterozoic Trans-Hudson Orogen are preserved within an obliquely exposed continental collision zone on Baffin Island (Canada). Early granulite-facies assemblages yield thermobarometric data and phase diagram information that define a steep, compressive P-T path segment. These assemblages are bracketed between ca. 1849 and 1835 Ma, and are interpreted to result from (1) heat advection by an 1865 +4/-2 to 1848 ± 2 Ma Andean-type granitic batholith, and (2) a ca . 1845 Ma crustal thickening event associated with accretion of an intra-oceanic arc terrane. A subsequent regional metamorphic event is characterized by the growth of retrograde, upper amphibolite-facies assemblages that define a clockwise, decompressive P-T path. Mineral growth is bracketed between 1820 ± 1 and 1813 ± 2 Ma, and is localized within deformation zones associated with the 1820 +4/-3 to 1795 ± 2 Ma collision of the Rae and Superior cratons. The metamorphic history of Baffin Island supports a progressive change from plate-margin to intraplate processes within an evolving convergent orogen during the Paleoproterozoic that is similar to those documented in younger collisional belts. |
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