Table T1.
Grain-size classes.
Midpoint (µm)
Midpoint
(
)
Lower
(µm)
Upper
(µm)
0.47
11.055
0.425
0.514
0.559
10.805
0.514
0.604
0.656
10.574
0.604
0.709
0.771
10.341
0.709
0.832
0.905
10.11
0.832
0.977
1.062
9.879
0.977
1.147
1.247
9.647
1.147
1.347
1.464
9.416
1.347
1.581
1.719
9.184
1.581
1.856
2.018
8.953
1.856
2.179
2.369
8.722
2.179
2.559
2.781
8.49
2.559
3.004
3.265
8.259
3.004
3.527
3.834
8.027
3.527
4.14
4.501
7.796
4.14
4.861
5.284
7.564
4.861
5.707
6.203
7.333
5.707
6.7
7.283
7.101
6.7
7.866
8.55
6.87
7.866
9.235
10.038
6.638
9.235
10.842
11.785
6.407
10.842
12.728
13.836
6.175
12.728
14.943
16.243
5.944
14.943
17.543
19.07
5.713
17.543
20.596
22.388
5.481
20.596
24.18
26.284
5.25
24.18
28.388
30.858
5.018
28.388
33.328
36.228
4.787
33.328
39.127
42.532
4.555
39.127
45.936
49.933
4.324
45.936
53.929
58.622
4.092
53.929
63.314
Notes: The size class ranges and midpoints for this study are taken directly from the analysette output files. As one reviewer noted, the midpoints are apparently calculated geometrically: class midpoint = (upper size class boundary + lower size class boundary)/2. A more sophisticated way to determine the midpoint of logarithmic spaced size class intervals would be, of course, the arithmetic mean: class midpoint = (upper size class boundary x lower size class boundary)1/2. However, we chose to use the machine output since the class spacing is small and any possible introduced error is negligible.