The pounding surf and breaking waves found on rocky coasts have inspired ocean lovers for generations. Erosion characterizes these high-energy environments, which are typically located on active margins with narrow continental shelves (on account of subduction). Rocky coasts may be composed of any rock type (i.e., sedimentary, igneous, or metamorphic) and are usually the site of complex tectonic landforms such as faults, folds, and igneous intrusions and extrusions. Bedrock composition, climate, and wave patterns dictate the profile of rocky coasts. Resistant bedrock combined with high-energy wind and wave activity will create a steep profile, whereas easily erodible rocks in low-energy environments will create a more gradual profile, for

example, the high cliffs of Kalaupapa National Historical Park (Hawaii) versus the gently sloping rocky coastline of Dry Tortugas National Park (Florida). In addition, glacial activity may produce steep, rocky coasts through the production of fjords and talus slopes, and carbonate coasts, dominated by skeletal and shelly materials may form eolianite dunes - calcium carbonate beach deposits that are lithified quickly into steep cliffs and bluffs by extreme wind action.

To learn more about areas in the National Park System with rocky coasts or the geologic features found there, select the Features shell.