Research at SER2L focuses on questions involving sediment sourcing, transport, mixing and accumulation, and related processes in geologically "young" (Pleistocene to modern) sediments found in contemporary sedimentary systems, including rivers and their floodplains, marshes, deltas, lakes, estuaries, coastal and open ocean settings. In addition to methods in geochemistry, sedimentology, geomorphology, and spatial analysis, we utilize the unique temporal and chemical charactersitics of both fallout and lithogenic radionuclides (7Be, 137Cs, 210Pb, 239,240Pu, 234Th, 232Th, 230Th, 228Th) to examine a range of geological, biological, and chemical processes in these environments.