Sediment

Algorithm

Descriptive statistics

Engineering

Aerospace engineering

Statistics

Sorting

Geomorphology

Microsoft excel

Operating system

Distribution (mathematics)

Range (aeronautics)

Particle size

Computer science

Geology

Paleontology

Grain size

Granulometry

Skewness

Mathematics

Frequency distribution

Particle-size distribution

Mathematical analysis

Operations management

Metric (unit)

Earth Surface Processes and Landforms

Grain size analysis is an essential tool for classifying sedimentary environments. The calculation of statistics for many samples can, however, be a laborious process. A computer program called GRADISTAT has been written for the rapid analysis of grain size statistics from any of the standard measuring techniques, such as sieving and laser granulometry. Mean, mode, sorting, skewness and other statistics are calculated arithmetically and geometrically (in metric units) and logarithmically (in phi units) using moment and Folk and Ward graphical methods. Method comparison has allowed Folk and Ward descriptive terms to be assigned to moments statistics. Results indicate that Folk and Ward measures, expressed in metric units, appear to provide the most robust basis for routine comparisons of compositionally variable sediments. The program runs within the Microsoft Excel spreadsheet package and is extremely versatile, accepting standard and non-standard size data, and producing a range of graphical outputs including frequency and ternary plots. Copyright © 2001 John Wiley & Sons, Ltd.

GRADISTAT: a grain size distribution and statistics package for the analysis of unconsolidated sediments