A Comparison between Log-hyperbolic and Model-independent Grain Size Distributions in Sediment Trend Analysis! (STA®)


  • Steven H. Hill
  • Patrick McLaren


Alluvial, aeolian, mean, sorting, skewness.


The log-hyperbolic distribution has proven useful elsewhere for the analysis of grainsize distributions of natural sediments. Descriptive statistics computed from grainsize distributions are the primary data source for the technique of Sediment Trend Analysis (STA®). In this paper descriptive statistics are computed for grainsize data taken from 4 different environments where the transport direction was known unequivocally. Two sets of descriptive statistics, one derived from log-hyperbolic curves fitted to grainsize data and one computed using a model-independent method were then examined to infer the direction and type of transport using the rules of STA. Both sets correctly predicted the direction of transport with essentially the same statistical significance. We conclude that the use of the log-hyperbolic distribution provides no advantage in the application of STA.