*5.4. Event 4—Atlantic Extensional Opening (?)*

The strike-slip faulting of Regimes 6 and 7 and the reverse faulting or Regime 8 indicate N–S compression and E-W extension. The presence of a strike-slip fault zone 1–3 m wide suggests that the offsets are relatively large (10–100s of meters) [35–37]. The contacts of the diabase dikes of Jurassic age are reactivated by the strike-slip faults of Regimes 6–7 indicating that the faulting and diabase dike intrusion in these regimes occurred 200–146 Ma or later. The NW-SE extension is compatible with the regional extension (based on local NE-SW diabase dike trends, [24]) affecting the study area during the initial opening of the Atlantic Ocean 200–175 Ma [34], Figure 5.
