Particle size scales and classification of sediment types based on particle size distributions: Review and recommended procedures

Abstract

This paper provides a review of different particle size scales, size class terminology and particle size distribution (‘textural’) classification schemes which are widely used in sedimentology, geomorphology, soil science, aquatic ecology and civil engineering. It is concluded that a revised system of size class nomenclature, based on the Udden (1898) and Wentworth (1922) schemes, provides the most logical and consistent framework for use with sediments and a wide range of other particulate materials. A refined scheme is proposed which has five first‐order size classes (boulder, gravel, sand, silt and clay), each of which has five second‐order subdivisions with limits defined at one phi intervals. The scheme is simple and intuitively easy to understand. The paper also provides a review of previous schemes that have been proposed to describe and classify sediments on the basis of the proportions of gravel, sand and mud, or sand, silt and clay using trigons (also termed ternary diagrams). Many of these schemes do not have a logical basis and provide limited or uneven resolution. New gravel, sand and mud and sand, silt and clay classification systems are proposed that are both more logical and provide greater discriminatory power than previous schemes; they are therefore more suitable for use in environmental and forensic investigations. A new Microsoft Excel® program, freely available to download from http://www.kpal.co.uk, allows rapid classification of sediments based on the proportions of gravel, sand and mud and sand, silt and clay proportions and graphical comparison of the data for different sample groups.

The fan-like forms in the southern margin of the Mazovian Lowland area (Central Poland): a new high-resolution textural-timing study

“…Structural elements of sediments observed in the field are usually not enough to identify a hiatus of sediment accumulation (Leighton et al 2013a, b). A more complete insight into (Marshall et al 2012;Blott and Pye 2012;Marcinkowski and Mycielska-Dowgiałło 2013).…”

A 9,000-year-old caribou hunting structure beneath Lake Huron

“…Grain size was performed on untreated samples on a Coulter LS 230 laser diffraction particle size analyzer. Sorting and sediment type were determined by using the Gradistat program (31). The 1-mm section was visually analyzed for lithic debris, charcoal, and fauna.…”

An aeolian or a glaciolacustrine record? A case study from Mieļupīte, Middle Gauja Lowland, northeast Latvia

“…Each sample was dry sieved for 15 minutes (Román-Sierra et al, 2013) and the individual sieve fractions were weighed with a precision of ±0.001 g. Subsequently the customised version of the R package "rysgran" (Gilbert et al, 2012) was used to calculate grain size parameters: mean grain size (Mz), sorting (σ) and skewness (Sk), following the logarithmic graphic method (Folk & Ward, 1957). Particle size distribution classification and terminology according Blott & Pye (2012) was implemented. Grain size data were presented as frequency and cumulative plots.…”