FY 1986

Accumulation rates of recent sediments in Puget Sound, Washington

Lavelle, J.W., G.J. Massoth, and E.A. Crecelius

Mar. Geol., 72(1-2), doi: 10.1016/0025-3227(86)90099-X, 59–70 (1986)

Sixteen profiles of unsupported Pb activity from long cores along the axis of the Main Basin of Puget Sound show that bottom sediments are accumulating at rates of 0.26 ± 0.03 to 1.20 ± 0.16 g cm yr. These rates and seven others published earlier suggest that highest accumulation occurs nearly midway along the length of this tidal-current-dominated basin. Bioturbated surface layers of cores are as deep as 40 cm, but biologic mixing rates are poorly determined. Individual Pb accumulation rates along the axis of the Main Basin range from approximately one to five times greater than the predicted areal-average accumulation rate based on estimates of recent sediment input from adjoining rivers and shorelines.