The Maritimes Basin of Atlantic Canada: Basin creation and destruction in the collisional zone of Pangea

During the final assembly of Pangea, the Maritimes Basin of Atlantic Canada was tectonically active for ~120 Ma from the mid Devonian to the early Permian, following terrane accretion and ocean closure in the region. The basin’s history records a prolonged period of convergence that post-dated the collision of Gondwana and Laurussia. The 12 km of basin fill was laid down in suites of periodically connected depocentres, and parts of the region experienced a polycyclic basin history, with repeated subsidence and inversion of fault-bounded depocentres, many associated with strike-slip faults. During two periods in the basin history, sedimentation overstepped fault zones under a regime of thermal subsidence to blanket much of the region. The basin fills are largely continental but include one open-marine interval with evaporite accumulation (Mississippian), as well as restricted-marine intervals, reflecting progressive loss of oceanic connection. Basinal architecture testifies to rapid subsidence against a backdrop of glacioeustatic influence in a paleo-equatorial setting. Volcanisms and intrusions were especially prominent during Devonian to Mississippian convergence, and halokinesis greatly influenced later basin development. A partial analogue for the Maritimes Basin is provided by modern Turkey and environs, situated in the Arabia–Eurasia collision zone, where strike-slip faults and basin formation record continued post-collisional convergence adjacent to the Zagros thrust-belt. Local crustal thickening, delamination of subducting crust, volcanism, extensional zones, and basin creation along crustal-scale faults are prominent in this region. Formed during Africa/Europe collision, the rapidly evolving basins of Paratethys provide a sedimentological analogue for the restricted setting.