The timing and timeframe of continental rifting is not too particularly constrained by the reconstructions by by by themselves,

Considering that the recognition of sea-floor anomalies that are spreading dates the postrift development of ocean crust. Usually the very first marine that is clear anomalies can be found instead far seaward from the margin, due either towards the existence of instead poor anomalies of uncertain beginning nearer to the margin (southern Newfoundland and Labrador margins) or even having less magnetic reversals (Scotian and north Newfoundland margins) through the Jurassic and Cretaceous Normal Polarities (

210-160 Ma and 118-83 Ma, correspondingly). More particular times for rifting would originate from exposures on land and/or drilling of syn-rift sedimentary sequences. Other quotes may be produced by extrapolating the prices of sea-floor spreading into the margin or by dating of sedimentary sequences or stones on land.

Such times declare that rifting for the older margins could have happened over a extended duration before the forming of ocean crust and could have impacted adjacent margin...