Tectonic setting of Middle Devonian to Lower Carboniferous rocks in the Magdalen Basin

Abstract

Seismic reflection data in the Gulf of St. Lawrence were used to construct an isopach map of the Horton Group (Middle Devonian-Early Carboniferous) in the Magdalen Basin. The map shows that the Horton Group was deposited in basins that developed parallel to the offshore extension of structural trends in New Brunswick and the Gaspe Peninsula. Horton Group strata were deposited in narrow linear fault bounded basins, presently up to 8 km deep, and in broad sag basins up to 3 km deep. Deformation of Horton Group rocks in the Magdalen Basin is concentrated in fault zones up to 20 km wide, and mainly affected deep subbasins, where thrust faults and possible flower structures are observed. -from Authors