and median is quite small for most 

 of these well sorted sediments. 

 Medians can be calculated by plot- 

 ting the weight percentages of size 

 grades in cumulative curves if the 

 value is desired. 



27. Sorting. The degree of sorting is 

 here indicated by the standard 

 deviation in phi units. These values 

 have been computed by IBM 650 

 digital computer programming. 



28. First quartile. The quartile diam- 

 eter s are indicated for a group of 

 representative samples covering 

 the entire area, but not for all 

 samples. Persons interested in 

 quartiles for all samples may pick 

 these from cumulati\e curves de- 

 rived from the tabulated size data. 



tribution in terms of weight percent 

 of total sample. These values may 

 be used to construct cumulative 

 curves of the size distribution of 

 each sample. 



31. Heavy mineral . This figure is 

 actually a connposite of the weight 

 percentages of heavy minerals 

 in each of the three finest 

 sand sizes. The individual per- 

 centages indicate that all heavy 

 minerals are contained predomi- 

 nantly in the 0.062- to 0.125-mm. 

 range . 



32. Light mineral . This is the weight 

 percent of total sample nnade 

 up of materials with a density 

 of less than 2.9. 



29. Third quartile . These values are 

 also shown only for a representa- 

 tive series as described above. 



30. Sieve weight percent . The tabu- 

 lated data show the size grade dis- 



33. Bioclastic. 



This symbol indi- 

 dominant bioclastic 



cates the 

 type. The symbols are: Fm :;; fo- 

 raminifera, Sh - shell fragments, 

 Co - coral fragments, Alg = algal 

 debris . 



27 



