Knowledge Bank

Data are presented for four shallow cores (33 cm) taken on March 25, 1982 from a salt marsh surrounding the St. Jones River, near Dover, Delaware. Recent sedimentation rates based on the combined Cs-137, Sr-90 beta activity indicate that the marsh along the St. Jones River is a region of exceptionally rapid deposition. Rates were based on the atmospheric fallout peak resulting from the Sept. and Nov. 1976 Chinese bomb tests, which prove to be a valid tool for chronology in a rapidly accreting area. Obtained depositional rates vary from 3.25±0.25 cm/yr for a point bar to 1.75 ± 0.25 cm/yr for a well-drained levee along the St. Jones River.