The Gander–Avalon Zone boundary in southeastern Newfoundland

Abstract

The Dover Fault, characterized by a 300–500 m wide mylonite zone, separates the Gander and Avalon Zones in northeastern Newfoundland and formed in association with the Precambrian regional deformation that overprints these zones. In southern Newfoundland, foliated granitic rocks of the Gander Zone are separated from non-foliated granites and clastic sedimentary and volcanic rocks (Connaigre Bay Group) of the Avalon Zone by a 50–100 m wide breccia zone called the Hermitage Bay Fault. Relationships along the Hermitage Bay Fault suggest that it is an Acadian structure that modifies the original Precambrian mylonite zone.