This is a study of sulfur cycling between organic and inorganic reservoirs in salt marsh and shelf break sediments. The objectives of the research are to understand the roles of organic and inorganic sulfur in controlling the redox cycling of inorganic trace elements in these benthic domains. Stable sulfur isotopes and natural radionuclide tracers (the radon 222 daughter series) will be used to probe the chemical processes involved. The research is based on the prediction that the rapid cycling of pyrite will cause those trace elements that are incorporated into the pyrite to be alternately oxidized and reduced. The research is significant not only because it will provide understanding about sulfur diagenesis in nearshore sediments, but also because it will improve current knowledge of elemental transfer across the land-sea boundary and knowledge of the sulfur flux from the marine environment to the atmosphere.
