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portion of the island, and is further evidence that wave energy has increased during the more
recent history of the island.
Tanner’s method of settling-eolian-littoral-fluvial (SELF) determination was applied to
all of the St. Vincent Island samples. A summary of the results of this analysis is provided in
Table 4.5. Ten of the St. Vincent Island samples collected in 2005 and 2006 had an eolian
component (samples 011006-06,09,10, 011106-09, 050505-01B, 02A, 02B, 03A, 04B, 05A).
The determination of which samples had an eolian component, was based on the application of
Tanners method of SELF determination. A plot of phi grain size versus cumulative percent was
produced for each sample. The plots were then compared to Figure 3.8 and each segment was
identified and labelled. Table 4.5 provides a summary of the results of these analyses. Those
samples with a segment “c” (as shown in Figure 3.8) were taken to represent sediments that had
an eolian component. Of these ten samples, four were collected from the base of a trench
(samples 011006-06, 011006-09, 050505-04B, 011006-10). The remaining six samples that
showed an eolian signature came from the tops of the ridges from which they were collected
(samples 050505-01B, 02A, 02B, 03A, 05A and 011106-09).
The results of the granulometric analyses were further analyzed using two of the plots
developed by Tanner (1991). Figure 4.34 is a “tail of fines” plot. This is a plot of suite mean vs.
suite standard deviation. All of the St. Vincent Island samples plot just outside of the field in
which river-deposited sediments are located. Figure 4.35 is a plot of skewness versus kurtosis.
With the exception of sets B and C, the St. Vincent Island samples plot within the beach/river
field. Set B plots in the eolian field. Set C plots outside the limits of the graph. Since sets B and
C are only represented by single samples, both with high positive skewness values, the results of
the SELF-analysis cannot be considered descriptive in the case of those ridge sets. These results
of the SELF-analysis generally seem to corroborate the conclusion that the sediments comprising
the beach ridge plain on St. Vincent Island have changed little over the history of the island, and
that the original source of these sediments was the nearby Apalachicola River mouth.
Previous studies have analyzed the grain size characteristics of various locations along
the Panhandle coast. Balsillie (1995) provides a summary of the granulometric results of these
studies. This data has been plotted on Figure 4.36. The data cover the Panhandle coast of
Florida. Figure 4.37 is a plot of relative sample location versus mean grain size. The plot shows
that grain size is largest closest to the Apalachicola River mouth and decreases with distance
away from the river mouth. Figure 4.38 shows relative location versus standard deviation
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