18 



Table 2-2. Grain Size Scales for Sediments 



ASTM (Unified) Classiflcation' 



U.S. Std. Sieve* 



Fine-grained Soil: 



Clay if PI 3 4 and plot of PI vs. U 

 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 



12 in (300 mm) 



3 in (75mm) 



3/4 in (19 mm) 



2.5 

 3 



3.5 

 4 (4.75 mm) 



10 (2.0 mm) 

 12 



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 



Phi (<1>) SUe 



-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 



0.75 

 1.0 



1.25 

 1.5 



1.75 

 2.0 



2.25 



3.25 

 3.5 

 3.75 

 4.0 

 4.25 

 4.5 

 4.75 

 5.0 

 6.0 

 7.0 

 8.0 

 9.0 

 10.0 

 11.0 

 12.0 

 13.0 

 14.0 



1 ASTM Standard D 2487-92. This is Ihe ASTM version of Che Unified Soil Classification System. Bolt syslems are similar (from ASTM (1993)). 



2. Note thai Bntish Standard, French, ind German DIN mesh sizes and dassificanons are different. 



3. Wenlwonh sues (m inches) cited in Kmmbein and Sloss (1963). 



Wentworth Classification 



Large Cobble 



Very Large Pebble 



Large Pebble 



Medium Pebble 



Very Coarse Sand 



Very Fine Sand 



Fine Sill 



Very Fine Silt 



Coarse Clav 



Medium Clav 



Monitoring Cruise at the New London Disposal Site, Seawolf Mound 1995 - 1998 



