This article represents a study of sediments from an environmental point of view. Although the environment may tend toward the formation of a given type of deposit, the characteristics of the sediments vary locally in accordance with the varying conditions in the environment. In the present example the principal control of the sediments appears to be the recurrent operation of tidal currents moving into and out of the bay, with their selective effects upon the materials in their path. This control is manifested by the size variations, the "sorting" of the sediments, and their organic carbon content.

In addition to serving as a method of describing sediments in detail, studies of environmental patterns may yield important data on ancient deposits. If a number of present-day environmental patterns were available, a given ancient deposit, analyzed in a similar manner by samples collected on a grid, may yield "patterns" which correlate with one or another of the known situations. Thus the study of areal variations within a deposit will yield a more reliable index of the ancient environment than the study of a few samples scattered widely over the area. In terms of the correlation of deposits, also, it may be seen that two or three scattered samples taken from a sediment having a pattern similar to Barataria Bay, might yield one beach sand, one channel sand and silt, and one finer mud With such limited data, one would almost invariably conclude that the three samples do not correlate, and yet they are not only correlative, but part of the same general environment. The pattern study would indicate at once the nature of the variations, and would account reasonably well for the apparent differences from place to place over the deposit.