Geotechnical and physical properties from whole-round consolidations samples of ODP Leg 110 holes (Table 1)

Sediments cored from the Barbados Ridge accretionary complex at ODP Sites 671, 672, and 676 are progressively underconsolidated with depth. Very low measured intergranular permeabilities contribute substantially to the probable excess pore-water pressures that account for the underconsolidated behavior. The estimated pore pressures immediately overlying the incipient decollement at the reference site are nearly equal to the overburden stress. Data show that the pore fluids within the fine-grained sediments of the complex are absorbing the tectonic shock of underthrusting as they are accreted, effectively leading to "lubricated subduction" of the underthrust Oligocene and older sediments. Lateral compression and dewatering by fracture permeability is taking place in the accreted section despite apparent underconsolidation, resulting in limited pore-volume reduction and sediment strengthening from east to west on the ridge.