Table 1. Sediment classification by particle size (Wentworth 

 classification) . 



Class 





Gra 



in size 



Phi 





Millimeters 



Gravel 



<-l 





>2.0 



Very coarse sand 









>1.0 ^2.0 



Coarse sand 



1 





>0.5 £1.0 



Medium sand 



2 





>0.25 <0.5 



Fine sand 



3 





>0.125 <0.25 



Very fine sand 



4 





>0.0625 £0.125 



Silt clay 



> 4 





£0.0625 



Table 2 . Degree of sediment sorting based on inclusive graphic 

 standard deviation (Folk, 1974) . 



Standard deviation 



Degree of sorting 



<0.35 



Very well sorted 



0.35 - 0.50 



Well sorted 



0.50 - 0.71 



Moderately well sorted 



0.71 - 1.00 



Moderately sorted 



1.00 - 2.00 



Poorly sorted 



2.00 - 4.00 



Very poorly sorted 



Table 3. Classification of sediment by skewness (Folk, 1974). 



Sk values 



Degree of skewness 



+1.00 - +0.30 



Strongly fine-skewed 



+0.30 - +0.10 



Fine-skewed 



+0.10 - -0.10 



Near symmetrical 



-0.10 - -0.30 



Coarse skewed 



-0.30 - -1.00 



Strongly coarse-skewed 



Table 4. Classification of sediment by kurtosis (Folk, 1974). 



Kg values 



Degree of kurtosis 



<0.67 



Very platykurtic 



0.67 - 0.90 



Platykurtic 



0.90 - 1.11 



Mesokurtic 



1.11 - 1.50 



Leptokurtic 



1.50 - 3.00 



Very leptokurtic 



>3.00 



Extremely leptokurtic 



