 Roughly 500 m of sediments line the floor of the depression, mostly turbidites.Channels cut through the southern end of the depression are remnants of turbidity flows originating from the Missoula floods, but there are also signs of more recent, local turbidity currents.There is also evidence of active seafloor spreading in this zone, indicating that the Cascadia Depression likely became separated from one of the spreading ridges that border the Blanco Transform Fault Zone.