Bottom sediments were collected from part of Barataria Bay, a tidal lagoon on the Mississippi delta. The organic carbon content of the samples was determined by a dry combustion method. The analytical data were used to prepare a map of the areal distribution of organic carbon in the environment. These data are correlated with the size attributes of the sediments; in general, the finest sediments have the largest content of organic carbon. The relation between average size and organic carbon appears to be exponential. The data are related to recent work on shoestring oil sands. The pattern of sediments in Barataria Bay supports earlier work by providing a suitable areal variation for the origin of the oil in the finer sediments, and its accumulation in the coarser sediments of the same general environment, by means of channels which serve as natural conduits for migration.