Late Neoproterozoic to Permian tectonic evolution of the Quebec Appalachians, Canada

This tectonic synthesis implies that the subdivision of the peri-Laurentian oceanic tracts proposed in other segments of the Appalachians should be applied with caution in Quebec and that the structural style, the number of oceanic domains and possibly the vergence of subduction change along the strike of the orogen. In particular, the similarities of the Thetford-Mines and Boil Mountain ophiolitic complexes and sedimentary covers and the lack of evidence for a major intervening suture are consistent with 'the maximum allochtony' hypothesis, i.e., the assumption that the southern Quebec ophiolites are rooted east of the Chain Lake massif. A geodynamic model involving the Taconian obduction of a large ophiolitic nappe(s), the docking of a peri-Gondwanan (Gander/Medial New England) terrane in early Salinic, the formation of large sedimentary basins (Connecticut Valley-Gaspé and Merrimack troughs) due to trench rollback and/or delamination during the late Salinic event and collision at the outer margin of composite Laurentia during the Acadian orogeny, can account for the protracted structural and metamorphic history of the Quebec Appalachians.