VOLCANICS 2 – PYROCLASTIC ROCKS - The Field Description of Igneous Rocks - page 102

3D 2D

Well sorted f = 0.36 Well sorted f = 0.36

Moderately sorted f = 0.74 Moderately sorted f = 0.74

= 1.15 = 1.15

Poorly sorted f Poorly sorted f

Figure 5.9 Models for estimating grain size sorting in 2D and 3D (sorting is
worked out using a cumulative frequency curve of the grain size - see Table 5.1).