Erosional landforms

The process of erosion can create different landforms along the coastline.

Headlands and bays

Cliffs along the coastline do not erode at the same pace. When a stretch of coastline is formed from different types of rock, headlands and bays can form.

Bands of soft rock such as clay and sand are weaker so therefore they can be eroded quickly. This process forms bays. A bay is an inlet of the sea where the land curves inwards, usually with a beach. Hard rock such as chalk is more resistant to the processes of erosion. When the softer rock is eroded inwards, the hard rock sticks out into the sea, forming a headland.

Waves attack the soft rock between sections of hard rock. This is differential erosion. The coastline changes over time, forming a bay where the erosion takes place, and a headland on either side.

Caves, arches, stacks and stumps

A crack expands into a cave. A cave expands into an arch. The arch collapses leaving headland and a stack. Wave-cut platform is exposed at low tide. The stack collapses into a stump.

Caves, arches, stacks and stumps are erosional features that are commonly found on a headland.

  • Cracks are formed in the headland through the erosional processes of hydraulic action and abrasion.
  • As the waves continue to grind away at the crack, it begins to open up to form a cave.
  • The cave becomes larger and eventually breaks through the headland to form an arch.
  • The base of the arch continually becomes wider through further erosion, until its roof becomes too heavy and collapses into the sea. This leaves a stack (an isolated column of rock).
  • The stack is undercut at the base until it collapses to form a stump.