ABSTRACT

A Programme which uses all available data from standard sedimentological analyses, regardless of the phi interval, and which computes statistical parameters by direct integration of a linear approximation to the cumulative curve is reviewed in conjunction with the significance of sieve intervals in grain size analysis for environmental interpretation.

It is claimed that the 0.25 phi interval produces more accurate and more meaningful results until such times as data can be obtained for values smaller than this interval.

Although it can be argued that fitting a higher order equation to the cumulative curve would produce more consistent results for the 0.25, 0.5 and 1.0 phi intervals, there is no practical or theoretical justification for choosing any particular family of curves to fit a cumulative curve of this description.

Therefore, a linear approximation is justified by its combination of simplicity and objectivity.