Sorting

Sorting is a property of unconsolidated sediments or sedimentary rock and describes the homogeneity in grain size present. Very poorly sorted rocks and soil indicates there is much difference in grain size and they are mixed. Well sorted rocks and soil indicates there is none to a small difference in grain size present and they are similar. For some indication one can take a look at the following graphical charts.

The sorting of a soil or rock depends on different factors. For example the rate, energy and duration of deposition, but also the kind of transport used to deposit the sediments. Well sorted rocks have often many spaces between its clasts so are very permeable and porous. Poorly sorted rocks have a more filled up matrix and therefor have a low permeability and low porosity.

References

• Tucker, M.E., 1996, Sedimentary rocks in the field, John Wiley & Sons, Chichester, 153 p.
• Compton, R. R., 1962, Manual of field geology, John Wiley & Sons, 378 p.