Surficial sediments, Chesapeake Bay, Virginia, are significantly sandier than previously reported. Sixty-five percent of the area as determined from 2,000 grab samples are sands when plotted on the ternary sand:silt:clay diagram. The mean graphic-mean is 3.17^phgr. Distribution of sediments is, in large part, a function of geomorphology with an apparently good correlation between depth and sediment type. Finer grained sediments are usually confined to the deeper channels. The exceptions to the depth-size relationship are the presence of fines in the shallow, marginal embayments such as Mobjack Bay and the absence of fines in the deep channel in the southeastern section of the bay. The occurrence of sands here is a function of infilling with sands from the area of the bay outh and, perhaps, of scour into older (Pliocene?) materials. Sediment distribution also reflects the local source with the shallow-water marginal sands derived from erosion of the banks and relict features.

Several large geomorphic features are distinguishable on the maps of sediment characteristics. These features include the deep channels, a large sand shield near Tangier Island, relict spits, the zone of influence of the bay mouth, and the possible existence of an ancient channel extending from Mobjack Bay. The number of samples in this study is an order of magnitude greater (2,000 versus 200) than previous studies, allowing a significantly better delineation of sediment types.

900 samples, biased away from 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 content. Total carbon content reached 10% in some samples, however, the average was 1.5%. Average organic carbon and sulfur contents were 1.0 and 0.34%, respectively.

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