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Pebble Count Data Norwalk River at South Wilton, Connecticut

INCHES PARTICLE MILLI-METER SIZE CLASS XS 1 % XS 1Mean % Cumu-lative XS 2 % XS 2Mean % Cumu-lative
  Silt/Clay < 0.062 S/C #   Size In XS 1     Size In XS 2
  Very Fine .062-.125 S     Class       Class  
  Fine .125-.25 A 6 9.52 0.1875 9.52 11 35.48 0.1875 35.48
  Medium .25-.50 N 8 12.70 0.375 22.22 1 3.23 0.375 38.71
  Coarse .50-1.0 D 4 6.35 0.75 28.57 3 9.68 0.75 48.39
.04-.08 Very Coarse 1.0-2 S     1.5 28.57     1.5 48.39
.08-.16 Very Fine 2-4       3 28.57 1 3.23 3 51.61
.16-.24 Fine 4-5.7 G     4.85 28.57     4.85 51.61
.24-.31 Fine 5.7-8 R     6.85 28.57 2 6.45 6.85 58.06
.31-.47 Medium 8-11.3 A     9.65 28.57     9.65 58.06
.47-.63 Medium 11.3-16 V     13.65 28.57     13.65 58.06
.63-.94 Coarse 16-22.6 E     19.3 28.57     19.3 58.06
.94-1.26 Coarse 22.6-32 L 1 1.59 27.3 30.16 1 3.23 27.3 61.29
1.26-1.9 Very Coarse 32-45 S 4 6.35 38.5 36.51 2 6.45 38.5 67.74
1.9-2.5 Very Coarse 45-64   8 12.70 54.5 49.21 3 9.68 54.5 77.42
2.5-3.8 Small 64-90 C - 4 6.35 77 55.56 1 3.23 77 80.65
3.8-5.0 Small 90-128 O L 7 11.11 109 66.67 1 3.23 109 83.87
5.0-7.6 Large 128-180 B E 10 15.87 154 82.54 5 16.13 154 100.00
7.6-10 Large 180-256 B S 6 9.52 218 92.06     218  
10-15 Small 256-362 B D 4 6.35 309 98.41     309  
15-20 Small 362-512 O E 1 1.59 437 100.00     437  
20-40 Medium 512-1024 U R                
40-160 Large to Very Large 1024-4096 L S                
  BEDROCK   BDRK                

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