Beach sediments in the study area have been studied by Cummings 

 and von Oesen (1973) and Balsillie (1975). Other reports from the 

 general area of northwest Florida with information applicable to the 

 study area include Stewart and Gorsline (1962), Koefoed and Gorsline 

 (1963), Gorsline (1964, 1966), and Stapor (1973). I. 



2. Methods. 



Sediment samples were collected in 8-ounce jars which were pushed 

 at least 4 inches into the substratum, removed, and capped. The 

 samples were frozen and stored until time for analysis. 



a. Particle Size, Carbon, and Carbonate Analysis . Samples for 

 sediment analysis were removed from the freezer and air dried over- 

 night. Using a microsplitter on a mechanical shaker, 15 to 20 grams 

 were separated for particle-size analyses. Another 4 grams were 

 separated to be ground for geochemical analyses. The split for 

 particle-size analysis was soaked in acetone, treated for 15 minutes 

 in an ultrasonic cleaner, and then rinsed. If the sand grains showed 

 any significant aggregation, the sample was carefully rubbed to 

 disperse the grains. The sample was then put through a series of 

 3-inch sieves of 1 phi unit intervals by agitation for 15 minutes on 

 the shaker. Each separated fraction on the sieves was weighed to the 

 closest milligram. From these data a frequency distribution was 

 compiled and other textural parameters computed. Since the silt-clay 

 fraction of the sands was less than 1 percent, no pipette analyses 

 were necessary. 



The analyses for total carbon and organic carbon content of the 

 beach sands were run on a Leco 750-100 90-second carbon analyzer. The 

 sediment split for chemical analyses was ground sufficiently to pass 

 through a 62-micrometer screen and then dried in an oven. To determine 

 total carbon content, approximately 0.2-gram samples were scooped out, 

 weighed to the nearest 0.1 milligram, and transferred to Leco 

 crucibles. The sediment was then combusted in a high-frequency 

 induction furnace at temperatures exceeding 1,600° Celsius. The carbon 

 dioxide driven off was carried off by dry, carbon dioxide-free oxygen 

 into a cylinder where the thermal conductivity of the gas mixture was 

 measured. A catalytic furnace in the oxygen train converted any carbon 

 monoxide to carbon dioxide. Readout was directly in percent carbon. 

 All samples and standards were run in triplicate. After 12 combustions 

 a high and a low standard were run and the bridge balance checked. 

 After about 110 combustions the tubing, sulphur and dust traps, and 

 combustion tube were cleaned. To determine the percent of organic 

 carbon, 0.2-gram samples were dried, weighed, treated with six drops 

 each of a 10-percent solution of hydrochloric acid, and warmed in a 

 Leco crucible. After removal of the soluble carbonate the residues 



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