Sorting
Sorting describes the distribution of grain size of sediments, either in unconsolidated deposits or in sedimentary rocks. Very poorly sorted indicates that the sediment sizes are mixed (large variance); whereas well sorted indicates that the sediment sizes are similar (low variance). The terms describing sorting in sediments - very poorly sorted, poorly sorted, moderately sorted, well sorted, very well sorted describe the amount of variance seen in particle sizes. The degree of sorting may also indicate the energy, rate, and/or duration of deposition, as well as the transport process (river, debris flow, wind, glacier, etc.) responsible for laying down the sediment
Different type of sorting.