Table 1. Grain-size scales-soil classification (U.S. Army, Corps of 

 Engineers, Coastal Engineering Research Center, 1977). 



Unified Soils 

 Classification 



ASTM 

 Mesh 



mm 

 Size 



Phi 

 Volue 



Wentworth 

 Classification 



COBBLE 



<Mm/f//^^^^^^ 



COARSE 

 GRAVEL 



p^^^^.9r6y-4.:.^-5^ 



256.0 -8.0 



64.0 -6.0 



BOULDER 



COBBLE 



14 



