The distribution patterns of sediment physical properties, deposition patterns, and sediment accumulation rates provide an integrating framework for investigations of toxic substance concentration and distribution. Over 2,000 surface-sediment grab samples (1.4 km grid) reveal that the bottom of Chesapeake Bay, Virginia, is significantly sandier than previously reported. About 65 percent of the area is sand. Nine hundred samples, selected to avoid the coarser sands, were analyzed for total carbon, organic carbon, and sulfur contents. There are strong correlations between these characteristics and sediment type, especially weight-percent clay. Additionally, there is a good relationship between the organic carbon and sulfur contents. The project includes an attempt at constructing a sediment budget using published values for silt and clay estuarine advection and contributions from shore erosion measured against the residual accumulations. The residual accumulation of silt and clay is an order of magnitude larger than previously estimated.