Cliff: steep natural rock faces, formation, types and notable examples

Formation and processes

Cliffs develop through a combination of geological forces and surface processes. Long-term erosion and weathering remove softer rock and soil, leaving resistant beds as steep faces. Sudden movements, such as faulting or landslide, can create or steepen a cliff quickly. Marine cliffs are often undercut by wave action, while river cliffs form on the outer bends of meanders.

Composition and types

Certain rock types commonly produce cliffs because of their hardness, jointing and bedding. Sedimentary examples include sedimentary rocks such as sandstone, limestone, chalk and dolomite. Resistant igneous rocks like igneous rocks including granite and basalt also form steep faces. Layering, fractures and the presence of weaker seams influence how cliffs break and retreat.

Distribution, landforms and hazards

Cliffs are fundamental to many landscapes and to hazards management. Coastal cliffs create sea cliffs, wave-cut platforms and sea caves; river cliffs shape floodplain dynamics; and highland cliffs form escarpments that control drainage and vegetation. They can generate waterfalls where rivers drop over resistant beds. Cliffs pose rockfall and landslide risks and require monitoring where people live or travel nearby.

Uses, recreation and conservation

Cliffs attract tourism, scientific study and recreational activities such as climbing and birdwatching. They provide nesting sites for seabirds and host distinct plant communities on their ledges. Management balances access with safety and conservation, since cliff ecosystems and archaeological sites can be fragile.

Notable examples illustrate scale and variety: coastal chalk and limestone cliffs in many countries, basalt escarpments in volcanic regions, and even extraterrestrial cliffs — the moon Miranda hosts the enormous scarp Verona Rupes on Miranda. Mapping conventions distinguish features: for instance, the Ordnance Survey draws cliffs and outcrops differently on maps. Each cliff reflects a local history of rock type, climate and the forces that shaped the landscape.

• Key processes: erosion, weathering, landslide.
• Typical rocks: sandstone, limestone, chalk, granite, basalt.
• Common settings: coasts, mountains, rivers.