Eleven gravity cores of the upper few meters of sediment from the Wilkinson Basin, southern Gulf of Maine, have been analyzed with respect to recent sedimentologic changes. The sediments are predominantly clays and silty clays of Holocene age. Clayey silt occurs within the upper meter of nine cores and is attributed to a "coarsening upward" phenomenon produced through extensive bioturbation by marine organisms. Winnowing and resuspension of clay-sized particles in the water column through the activities of infaunal and epifaunal organisms have created the postdepositional sedimentary facies of clayey silt. Conditions of relative basinal stability, allowing for substantial colonization of organisms, may cause postdepositional sedimentological changes generally attributed to changes in shelf dynamics. Analysis of shelf-basinal sedimentology should consider the postdepositional sedimentary modification due to organic activity in addition to alternate depositional processes.