Chapter Eight Rocky Shores

Publisher Summary Although the study of rocky shores has seen significant progress, the complex process interactions and the variability imposed by rock characteristics and climatic conditions may necessitate reliance, at least in part, on the interpretation of sometimes ambiguous field evidence. A fine example in this regard concerns the roles of tsunamis or exceptional storms in boulder emplacement on rocky shores or in the sculpting of these shores. Determining the differences in the evolution of rocky shores as a function of tsunami, storm, or simply structurally or chemically controlled marine erosion and weathering requires many more studies over a variety of field sites and climatic conditions. The central debate on rocky shore processes has essentially focused on the respective roles of weathering and marine processes, notably mechanical wave erosion against various backgrounds of rock lithology and resistance. A measure of the large variability of process and form is highlighted by the study of Dickson on the morphology of near-horizontal basalt and calcarenite shore platforms around the Lord Howe Island. Recognition and description of rocky shorelines and notably their deposits are crucial for correctly interpreting the geological history of oceanic and volcanic arc islands.