Excess ²¹⁰Pb activity from grab samples taken from the shelf and slope off the Sepik River in 1997. Low ²¹⁰Pb activities and reduced clay concentrations in the canyon extending off the mouth suggests sediment delivery by gravity flows. The westward fining and dramatically higher ²¹⁰Pb activities suggest deposition from a surface plume.
 

Percent clay from grab samples taken from the shelf and slope off the Sepik River in 1997. Low ²¹⁰Pb activities and reduced clay concentrations in the canyon extending off the mouth suggests sediment delivery by gravity flows. The westward fining and dramatically higher ²¹⁰Pb activities suggest deposition from a surface plume.