Geologic characteristics of benthic habitats in Glacier Bay, southeast Alaska

Wentworth Class

Size (mm)

Size (phi)

Fraction of mm

very fine silt

0.0039 mm

0.0078 mm

8.0 phi

7.0 phi

1/256

fine silt

0.0078 mm

0.0156 mm

7.0 phi

6.0 phi

1/128

medium silt

0.0156 mm

0.031 mm

6.0 phi

5.0 phi

1/64

coarse silt

0.031 mm

0.0625 mm

5.0 phi

4.0 phi

1/32

very fine sand

0.0625 mm

0.125 mm

4.0 phi

3.0 phi

1/16

fine sand

0.125 mm

0.250 mm

3.0 phi

2.0 phi

1/8

medium sand

0.250 mm

0.500 mm

2.0 phi

1.0 phi

1/4

coarse sand

0.500 mm

1.00 mm

1.0 phi

0.0 phi

1/2

very coarse sand

1.00 mm

2.00 mm

0.0 phi

–1.0 phi

1

granule

2.00 mm

4.00 mm

–1.0 phi

–2.0 phi

2

pebble

4.00 mm

–2.0 phi

4

cobble

> 16 mm

~–6 phi

16

boulder

> 256 mm

–8 phi

256