Structural trends and basement rock subdivisions in the western Gulf of St. Lawrence, northern Appalachians

Abstract

We compiled industry seismic and LITHOPROBE deep seismic data in the southwestern Gulf of St. Lawrence, and interpreted them together with gravity, magnetic and industry well data, to study the deepest sediments, which are assignable to the Horton Group of Late Devonian-Early Carboniferous age, and the basement rocks of the northern Appalachians. Three upper crustal basement blocks with differing seismic character and orientation of geological structures were identified. This compilation enabled us to address the problem of the formation of the Magdalen Basin. Several Horton Group subbasins, bounded by normal faults, indicate a widespread crustal extension phase which coincided with the early development of the Magdalen Basin. -from Authors