Rates and patterns of estuarine sediment accumulation

Abstract

Estuarine sedimentation rates are estimated for vertical increments of sediment cores by adjusting average rates between dated horizons with the ratio of pollen concentration to concentration of sediment. The method assumes independent influxes of pollen and sediment into the estuary, similar patterns of transport and deposition for both pollen and fine sediment, a uniform influx of pollen over the time interval between dated horizons, and preservation of the majority of pollen entering the estuary.Comparisons of detailed, pollen‐derived sedimentation rates with historical records of climatic and anthropogenic events in upper Chesapeake Bay show that highest rates of sediment accumulation occur in upper and middle stretches of tidal tributaries and coincide with major storms and periods of intensive land clearance when > 20% of total land area in a given watershed is deforested and under cultivation.