Particle size categories for various detrital sedimentary rocks.

Detrital sedimentary rocks are described effectively in terms of compositional, textural, and structural attributes. In the procedure presented, rock-framework types, grain-boundary contacts, cement composition, and bedding characteristics are recorded. Standardized visual comparison charts aid in determining roundness, colour, and percentage distributions of particle composition and size. Quantified descriptions are more useful than field names in comparing stratigraphic sections, analyzing sedimentary parameters, and adapting observations to classifications.

Particle size is the primary basis for distinguishing among various detrital sedimentary rocks. (Breccia photo by E. J. Tarbuck; all other photos by Dennis Tasa)
Engineering geology
Glaeser, J. Douglas. “PROCEDURE FOR DESCRIPTION OF DETRITAL SEDIMENTARY ROCKS.” Proceedings of the Pennsylvania Academy of Science, vol. 36, 1962, pp. 213–217. JSTOR, www.jstor.org/stable/44112152. Accessed 8 Jan. 2020.