25 



Table 2-3 

 Grain Size Scales for Sediments 



ASTM (Unified) Classification' 



U.S. Std. Sieve 2 



Phi (D) Size 



Wentworth Classification 3 



Fine-grained Soil: 



Clay if PI 3 4 and plot of PI vs. 

 LL is on or above "A" line 

 Silt if PI < 4 and plot of PI vs. 

 LL is below "A" line 



and the presence of organic matter 

 does not influence LL. 



3 in (75mm) 



3/4 in (19 mm) 



2.5 

 3 



4 (4.75 mm) 

 5 



10 (2.0 mm) 



12 



14 



16 



18 



20 



25 



30 



35 

 40 (0.425 mm) 



45 



50 



60 



70 



80 



100 



120 



140 



170 

 200 (0.075 mm) 



230 



270 



325 



400 



4096. 

 1024. 



256. 



128. 

 107.64 

 90.51 

 76.11 

 64.00 

 53.82 

 45.26 

 38.05 

 32.00 

 26.91 

 22.63 

 19.03 

 16.00 

 13.45 

 11.31 



9.51 



8.00 



6.73 



5.66 



4.76 



4.00 



3.36 



2.83 



2.38 



2.00 



1.68 



1.41 



1.19 



1.00 



0.84 



0.71 



0.59 



0.50 

 0.420 

 0.354 

 0.297 

 0.250 

 0.210 

 0.177 

 0.149 

 0.125 

 0.105 

 0.088 

 0.074 

 0.0625 

 0.0526 

 0.0442 

 0.0372 

 0.0312 

 0.0156 

 0.0078 

 0.0039 

 0.00195 

 0.00098 

 0.00049 

 0.00024 

 0.00012 

 0.000061 



-12.0 

 -10.0 

 -8.0 

 -7.0 

 -6.75 

 -6.5 

 -6.25 

 -6.0 

 -5.75 

 -5.5 

 -5.25 

 -5.0 

 -4.75 

 -4.5 

 -4.25 

 -4.0 

 -3.75 

 -3.5 

 -3.25 

 -3.0 

 -2.75 

 -2.5 

 -2.25 

 -2.0 

 -1.75 

 -1.5 

 -1.25 

 -1.0 

 -0.75 

 -0.5 

 -0.25 



0.0 

 0.25 



0.5 

 0.75 



1.0 

 1.25 



1.5 

 1.75 



2.0 

 2.25 



2.5 

 2.75 



3.0 

 3.25 



3.5 

 3.75 



4.0 

 4.25 



4.5 

 4.75 



10.0 

 11.0 

 12.0 

 13.0 

 14.0 



Large Cobble 



Very Large Pebble 



Large Pebble 



Medium Pebble 



Very Coarse Sand 



Very Fine Sand 



Fine Silt 



Very Fine Silt 



Coarse Clay 



Medium Clay 



1. ASTM Standard D 2487-92. This is the ASTM version of the Unified Soil Classification System. Both systems are similar (from ASTM (1993)). 



2. Note that British Standard, French, and German DIN mesh sizes and classifications are different. 



3. Wentworth sizes (in inches) cited in Krumbein and Sloss (1963). 



Monitoring Cruise at the New London Disposal Site, 1992 - 1998 



