Observations from rifted margins reveal that significant structural and
crustal heterogeneity develops through the process of continental
extension and breakup. While a clear link exists between distinct margin
structural domains and specific phases of rifting, the origin of strong
segmentation along the length of margins remains relatively enigmatic
and may reflect multiple competing factors. Given that rifting
frequently initiates on complex tectonics sutures, structural
inheritance is frequently invoked as an origin of margin segmentation,
although to date no studies have clearly elucidated the link between
inheritance and 3D rifted margin geometries. Here, we use recent
observations from the Labrador Sea and thermal-mechanical simulations of
continental rifting to constrain the effects of inherited variable
lithospheric properties on margin segmentation. The modelling results
demonstrate that N-S variations in lithospheric thickness, crustal
structure, and rheology within the pre-rift Canadian Shield produce
sharp gradients in rifted margin width and the timing of breakup,
leading to strong margin segmentation across a range of
geophysically-constrained rift parameters.