Extension of Sediment Geochronology to Coarse-Grained Sediments

Knowledge of seabed dynamics in nearshore environments is needed to address problems ranging from to the evolution of coastal geomorphology to the changing nature of seabed acoustical properties. One successful approach, used primarily in fine-grained sedimentary environments, has been the application short-lived particle-reactive radioisotopes to quantify sediment deposition and accumulation rates, and to measure the depth and intensity of physical and biological mixing. Unfortunately, the utility of this approach in coarser sediments typical of coastal environments has been hindered by the low inherent concentration of these isotopes in sandy sediments, and the relatively high lower limit of detection using traditional decay counting techniques. The proposed study would attempt to extend this approach into sandy sedimentary environments by taking advantage of a relatively new measurement technique, high-resolution inductively coupled plasma-mass spectroscopy (ICP-MS).