Did the Hudson Strait in Arctic Canada record the opening of the Labrador Sea?

• Hudson Strait is characterized by half-grabens.
• Hudson Strait bears similarities with the Baffin Bay area.
• Half-graben development may be linked with the opening of the Labrador Sea.

The Hudson Strait–Evans Strait–Foxe Channel (HEF) is a major composite topographic feature that connects Hudson Bay and Foxe Basin with the Labrador Sea. Hudson Strait is underlain by several fault-controlled sub-basins with a half-graben geometry. The sedimentary succession in the sub-basins is thicker than the one preserved onshore and reaches a maximum of ∼2.6 km in the eastern part of the Hudson Strait. The lower part of the offshore succession correlates with Paleozoic rocks exposed in nearby islands but the nature and age of the upper part remains poorly constrained. Faults have a clear morphological expression, strike WNW and ENE, dip predominantly toward the north and record an extensional tectonic event that predates an episode of shortening. A model is proposed linking half-graben development to the initial stages of extension in the future Labrador Sea and subsequent inversion to the kinematic decoupling of the Labrador Sea from the Canadian landmass by the Ungava Fault Zone.