The Boulder Beach: A Fundamentally Distinct Sedimentary Assemblage.

Five boulder beaches located along the coast of New South Wales, Australia, were examined in order to determine if beaches composed of boulders differ in basic sedimentological structure and behavior from beaches composed of cobbles or pebbles. Each beach is aligned obliquely to the approaching waves and is composed of locally derived sediment. Investigation of beach-particle size, morphology, and roundness, along with foreshore slope, reveals consistent up-beach particle fining, positive size skewness, absence of shape zoning. absence of sphericity grading, and low foreshore slope. These characteristics of the five studied boulder beaches contrast markedly with the known characteristics of beaches composed of finer sediment, which suggests that boulders appear to form fundamentally distinct coastal sedimentary assemblages. [ABSTRACT FROM AUTHOR]