The Jeanne d＇Arc Basin preserves over 20 km of Mesozoic-Cenozoic predominantly clastic sediments. In common with other Canadian frontier basins, a significant portion of these sediments are overpressured. At the Hibernia oil field, discovered in 1979, these abnormal pressures are capped by the Fortune Bay Shale and approach the overburden pressure. Hydrocarbon pools at Hibernia largely occur above this overpressured zone. In the adjacent Nautilus Fault block (downthrown), the top to the overpressures is at similar depths, however, stratigraphically they are sealed by the younger Nautilus Shale. The origin of the overlying hydrocarbons has been shown to be the Egret Member source rock of Type II kerogen. Through an investigation of the interplay among sedimentation, compaction, seal development and thermal history of basin sediments we have derived models of formation pore pressure and hydrocarbon generation history of the Hibernia-Nautilus area. Pressure models are derived through a transient diffusion formulation executed through the combination of Darcy＇s law with the continuity equation to conserve total fluid mass. The modelled excess pressure and hydrocarbon generation histories for cap and source rock lithologies are able to reproduce measured, present-day maturity, temperature and pressure depth profiles. For the Nautilus Fault block, excess pressures are likely due to the combined effects of compaction disequilibrium and hydrocarbon generation. Excess pressuring occurred from 80-40 Ma resulting in extensive seal fracturing/migration events. We postulate that these events were responsible for charging the adjacent Hibernia block which, at that time, had no hydrocarbon generation and little excess pressuring activity. Such activity in the Hibernia block developed during the last 15-20 Ma and is currently permitting leakage of mature hydrocarbons into Hibernia＇s reservoirs. Hydrocarbon generation ceased in the adjacent Nautilus block as the source rock was fully depleted at 35-40 Ma. Sedimentation rates are likely responsible for present-day overpressures at this location.