VARIABILITY IN THE AGE OF RIVERINE ORGANIC MATTER FROM RIVERS OF THE EAST COAST OF THE UNITED STATES

The age of riverine organic matter provides critical information on the residence time of terrestrial organic matter and is also used to evaluate the contributions of terrestrial organic matter in ocean basins. Here we present 14C data on particulate organic, dissolved organic and dissolved inorganic carbon from a number of United States east coast rivers. Although these rivers occupy a small geographic range, they display a large variation in 14C values. Many systems have significantly depleted 14C values indicating the potential for contributions from relic pools. The high within and across system variation, however, makes it difficult to either evaluate landscape controls on the export of relic carbon from terrestrial catchments or estimate the amount of terrestrial carbon in the associated ocean margin.