were conducted at a sealed borehole penetrating the decollement at the Barbados

accretionary complex support the conclusion by Fisher and Zwart (1996) that significant

permeability increase can occur within the decollement at pore pressures below lithostatic

pressures (Screaton et al., 1997). Studies based on fluid budgets shows that fluid flux

varies with both arcward distance and through time (Saffer and Bekins, 1999). In

addition, fluid budget studies suggest that initiation of connected flow conduits is delayed

with respect to the time of accretion and may be related to burial below a critical depth,

where channelized fluid escape is more efficient than diffuse flow to the sea floor or

where sediments may behave brittlely (Saffer and Bekins, 1999). Even though previous

modeling studies have investigated the production of overpressures, these models did not

indicate when the overpressures are generated in the evolution of the complex and thus,

the connectivity between excess pore pressures and episodic fluid flow is not well

understood. Models used by Henry and Wang (1991), Shi and Wang (1994), and

Stauffer and Bekins (2001) focused on processes that take place at the toe of the prism

during initial offscraping. Bekins et al. (1995) focused on steady-state pore pressures and

transient fluid flow assuming instantaneous decollement permeability after the entire

prism had grown. However, to fully understand the development of pore pressures and

thus, hypothesized episodic fluid flow, one should examine the development of pore

pressures both at the toe and deeper parts of the accretionary complex through both space

and time. Thus, in this study I modeled 50 km of the accretionary complex as a time-

dependent evolving prism. A combined prism growth and fluid flow model was used to

examine the development of pore pressures. Mechanisms for episodic fluid flow were

examined during the evolution of the accretionary complex by including hydrofracture or