At the toe of the northern Barbados accretionary complex, temperature and pore water chemistry data indicate that fluid flow is channeled along the d¿collement and other shallow thrust faults. We examine mechanisms that may prevent consolidation and maintain high permeability over large sections of the d¿collement. High-resolution bulk density data from five boreholes show that the d¿collement is well consolidated at some sites while other sites remain underconsolidated. Underconsolidated d¿collement behavior is associated with kilometer-scale negative-polarity seismic reflections from the d¿collement plane that have been interpreted to be fluid conduits. We use a coupled fluid flow/consolidation model to simulate the loading response of a 10-km-long by 680-m-thick slice of sediment as it enters the accretionary complex. The simulations capture 185 ka (5 km) of subduction, with a load function representing the estimated effective stress of the overriding accretionary prism (3.8¿ taper angle). Simulation results of bulk density in the d¿collement 3.2 km arcward of the deformation front are compared with observations. The results show that persistent high pore pressures at the arcward edge of the simulation domain can explain underconsolidated behavior. The scenario is consistent with previous modeling results showing that high pore pressures can propagate intermittently along the d¿collement from deeper in the complex. Simulated seaward fluxes in the d¿collement (1--14 cm yr-1) lie between previous estimates from modeling studies of steady state (1 m yr-1) flow. Maximum simulated instantaneous fluid sources (2.5¿10-13 s-1) are comparable to previous estimates. The simulations show minor swelling of incoming sediments (fluid sources ~-3¿10-15 s-1) up to 3 km before subduction that may help to explain small-scale shearing and normal faulting proximal to the protod¿collement. ¿ 2001 American Geophysical Union