Acadian Deformation in the Anticosti Basin, West Newfoundland

Abstract

It has been traditionally assumed that the limit of the Acadian deformation of the Anticosti basin corresponded with the western limit of the onland exposures in western Newfoundland. Offshore seismic surveys have previously failed to provide evidence to allow any modification of this concept. Recent reprocessing of old marine seismic data reveals that Acadian thrust deformation extends about 80-100 km to the west of Newfoundland. This is entirely compatible with Acadian structures such as the Tenmile Lake and Great Northern faults and their azimuthal projection from their intersection with the shoreline. Both surface analyses and seismic interpretation indicate that these structural features are basement-cored, high-angle reverse faults with minimal foreshortening. Characteristic hanging-wall drape anticlines and footwall synclines can be identified both in outcrop and in the subsurface, indicating structurally focused petroleum potential in the offshore.