ABSTRACT

Size-frequency distributions of clastic rocks and sediments customarily are described with respect to the log-normal distribution or the normal phi distribution that results from logarithmic transformation of size variates. Clastic materials derived through mechanical disintegration, crushing, or volcanic explosion might be described better in terms of Rosin's law of crushing. A parametric statistical test, based upon regression analysis of size-frequency data and conducted with a digital computer, provides evidence that size-frequency distributions of artificially crushed material fit Rosin's distribution and that distributions of some regolithic, pyroclastic, and glacial debris fit Rosin's distribution with various degrees of approximation. Further use of the technique described may suggest new ways of studying initial fluviatile sorting and the formation of pyroclastic deposits.