Transverse bars are subtle digitate features which extend at high angles to the beach in areas which are characterized by low wave energy, shallow offshore slopes and an abundant sand supply. Simple and reticulated transverse bars in Franklin County, Florida were investigated during this study. Field examination of these transverse bars included water and grain motion and wave parameters associated with transverse bars. In addition, examinations of the bar form and internal structure were conducted. Laboratory procedures included granulometric analysis and subsequent statistical treatment of laminar sediment samples collected from both the simple and the reticulated bars. Analysis of aerial photography, x-ray photographic analysis of cores collected from the bars, and model studies of the currents generated over reticulated bars were also conducted. Granulometric investigation of the simple and the complex bars revealed several interesting factors. The simple bar samples displayed easily interpreted characteristics. The mean grain size for,the individual samples was regulated primarily by the intensity of wave reworking: bar axis samples were coarsest at the shoreward end and finest at the seaward end. Standard deviation displayed a similar trend. The reticulated bar samples cannot be statistically separated one from another. All of the granulometric characteristics displayed only subtle differences from one sample to another. Mean grain sizes were finer for the reticulated bars than for the single orientation bars. No trends were discernable within the reticulated bar samples set and granulometric characteristics could not be correlated with the topographic expression of the transverse bars. This condition is (in this author's opinion) due to the presence of two predominant wave approach directions. Sediment distributions are altered and then mixed back together each time the wave approach direction changes and sediment transport occurs. There appears to be only one requirement for the formation of complex reticulated transverse bars in addition to those conditions necessary for the formation of simple bars. That one requirement is the presence of two predominant wave approach directions. The mechanisms which operate over the complex bars are basically the same mechanisms which operate on simple bars. An additional operation on the complex bars is the destructive effects of wave energy on that bar set which is not aligned with the ambient wave approach direction. Thus at any one moment one bar set is being constructed, while the second set is undergoing destruction due to wave energy being expended and sediment transported across the bar in an axis-normal direction. Wave parameter studies allowed the determination that wave energy density is augmented over the axis of relatively short bars. This energy density increase is due to the constructive interference of crossing waves, and not due to shoaling effects. This process works on both simple and complex transverse bars. Two theories of transverse bar formation were examined. The field data and observations of the present author are in agreement with the Niedoroda method of formation by the refraction of waves over a preexisting bathymetric high. The Barcilon and Lau theory, in the present author?s opinion, does not stand the test against field data, and is not a viable method of transverse bar formation.

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