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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. [ABSTRACT FROM AUTHOR]