The “Pink Granite” Coast (Northern Brittany)

Abstract

The “Pink Granite” coast, in northern Brittany, some 30 km long, is more familiar to tourists than to geomorphologists. The following paper highlights the limitations of the explanations propounded to the 700,000 visitors who annually come to admire the fantastic shapes into which the coarse-grained granites, which are reddish in fact, have been eroded. The occurrence of assemblages of boulder piles involves their subsurface initiation by differential weathering and the stripping of the saprolite by marine processes. Following their exhumation, basins and flutes have developed on the granite outcrops under subaerial conditions. At all scales of analysis, the “Pink Granite” coast exhibits an assemblage of landforms, which are not specific of coastal environments, illustrating the concept of convergence or equifinality, that is, the production of similar landforms by different processes.