program which relates actual pressure and time decay to equivalent fall 

 diameter, statistical parameters descriptive of the sediment size- 

 distribution curve are calculated. An analogous computer program for 

 sieve data computes the same granulometric parameters which are: median 

 and mean diameter (central tendency); standard deviation (dispersion); 

 skeimess (asymmetry); and kurtosis (peakedness) . These parameters are 

 shown symbolically below: 



MEAN 



X^ = 2 Xi fi 

 i=l 



STANDARD DEVIATION 

 Oa =/~n o 



1 (X,-X) fi 



i=l 



KURTOSIS 



i=l_ 

 4 



n 



SKEWNESS 



ci = 1 (Xi-X)^ fi 

 1=1 



"7 



fj^ = frequency by weight of grains present in interval. 



n = number of sample classes. 



X^ = diameter of midpoint of sample interval, in phi units. 



Xj) = mean particle diameter expressed in phi units. 



a A = standard deviation expressed in phi units. 



aj = ske\tfness. 



cto = kurtosis. 



No allowance is yet made for the effect of sample mass on the fall 

 diameter. Median diameter is also computed. While it is recognized that 

 that measure of central tendency is not as sensitive as the mean, median 

 is used extensively in this paper to facilitate comparison with earlier 

 studies and available published data where median is also cited. Never- 

 theless, all samples analyzed by and for CERC in this Florida program 

 and listed in Appendix B show mean as well as median values. 



Certain samples were also processed in the laboratory for determina- 

 tion of the acid-soluble content. Visual examination pf the samples shows 

 that for south Florida shelf sediments the acid-soluble content is almost 

 entirely calcium carbonate skeletal material. Weight percentage of acid- 

 soluble constituents was determined by adding a dilute solution of hydro- 

 chloric acid to a carefully dried and weighed sediment sample of 10 to 20 

 grams. Acid was added until all physical evidence of reaction had ceased. 

 Acid was then decanted, the residue thoroughly washed in distilled water, 

 dried, and weighed. The soluble content was calculated as the percent, by 

 weight, of the total sample lost to acid solution. 



