High-resolution historical records from Pettaquamscutt River basin sediments: 1. Pb and varve chronologies validate record of Cs released by the Chernobyl accident

Cesium-137 derived from the explosion of the Chernobyl reactor in 1986 was preserved in anoxic sediments from a coastal environment in southern Rhode Island. Although the radioactive plume was detected in surface air samples at several locations in the United States, this is the first known record of a Chernobyl Cs peak in sediments from North America. The inventory of Chernobyl Cs that was preserved in the Pettaquamscutt River is small compared to European counterparts and should only be detectable for the next 15–20 yr. However, the presence of two Cs peaks (1963 and 1987) identifies a well-dated segment of the sediment column that could be exploited in understanding the decomposition and preservation of terrestrial and aquatic organic matter. Different methods for calculating the Pb chronology were also evaluated in this study and checked against independent varve counting. The end result is a detailed chronology of a site well 0016-7037/05 $30.00 .00 suited for reconstruction of historical records of environmental change. Copyright © 2005 Elsevier Ltd