The Dover Fault: Western Boundary of the Avalon Zone in Northeastern Newfoundland

Abstract

Basement rocks of the Hare Bay Gneiss Complex and associated granitic intrusive rocks on the western side of Bonavista Bay, northeastern Newfoundland, are separated from clastic sedimentary and volcanic rocks of the Avalon Zone (Love Cove and Musgravetown Groups) by a 300–500 m wide mylonite zone called the Dover Fault. The Dover Fault juxtaposes rocks of contrasting lithology and metamorphic, intrusive, and structural histories and represents the boundary between the Gander Zone and the Avalon Zone of the Newfoundland Appalachian System. Structural relationships across the fault zone indicate that early movement on the Dover Fault was contemporaneous with deformation of the Love Cove Group. Relationships elsewhere in the Avalon Zone indicate that the Love Cove Group was deformed in Hadrynian time and hence the Dover Fault was probably initiated as an Hadrynian structural feature, probably related to Hadrynian orogeny on the eastern side of the Appalachian system.