The Carboniferous-Permian stage in the evolution of the Paran¿ Basin is characterized by the long-wavelength deposition of up to ~2.5 km of sediment in the continental interior. The tectonics of the region during this time were dominated by convergence and active subduction along the nearby Panthalassan margin of Gondwana. While subsidence in the basin is clearly related to the major tectonic events at the plate margin, there is a distinct delay between the onset of subduction and the initiation of basin deposition. This, and the nature of basin stratigraphy, suggests that the large-scale subsidence may have been the dynamic response of the lithosphere to mantle flow associated with the penetration of accumulated slab material through the phase change at 660 km depth. We present numerical experiments of mantle convection which show that subducting slabs can stagnate at the 660 km depth phase change and intermittently penetrate through. The associated (negative) dynamic topography remains at relatively low amplitudes as the subducting material pools and then increases rapidly to a maximum during the phase of penetrative flow. We find that the predicted delay time between initial descent of the slab and the maximum surface topography corresponds with evidence from the geological record. Several models of sedimentation based on the evolving dynamic topography are presented, and a simulation generated using infill rates independently estimated for the basin provides a close fit to the amplitude and horizontal length scale of material accumulation in the Paran¿ Basin.