Parámetros granulométricos: comparación entre el método gráfico y el método de los momentos

Abstract

The two classical methods, moment and graphic, used to determine grain size parameters are revised and compared, using 282 beach, inner shelf and aeolian samples. Mean size and sorting values are similar, but skewness and kurtosis show great differences after applying the method. Furthermore, classification ranges for kurtosis and skewness obtained by moment's method have not been described. Normalisation improves kurtosis but not skewness when moment analysis is used. Separate treatment of uni modal, bimodal and polymodal distributions does not help to get better results. Consequently the graphic method should be preferably used until a sedimentary interpretation of third moment is obtained.