Abstract

The Paleozoic tectonic history of the Moncton Basin is characterised by periods of subsidence that accommodated much of the sedimentary succession, punctuated by periods of tectonic contraction, uplift and basin inversion recorded by unconformities or disconformities in the basin section. Five periods of basin inversion are identified: a mid-Tournaisian inversion, resulting in the Horton/Sussex unconformity; a late Tournaisian to early Visean inversion, resulting in the Sussex/Hillsborough unconformity; a late Visean to Serpukhovian inversion, resulting in the emplacement of basement slices allochthonously overlying basin units and the formation of the Mabou/Cumberland unconformity; a period of basin inversion and salt tectonics probably associated with the development of a mid-Bashkirian disconformity; and latest Carboniferous or Permian (Alleghanian) contraction. The pattern of subsidence and deposition punctuated by contraction and basin inversion suggests that the Moncton Basin was subjected to a consistent regional-scale kinematic movement picture throughout Carboniferous time. This was probably the result of episodic transpression occurring in a restraining bend of the regional Minas fault system in response to latest Devonian to Pennsylvanian dextral strike-slip movements on that fault system.