You are here: AQA GCSE Geography PLCs > Coasts > C8 Example Answer
Explain the formation of a headland and bay / wave-cut platform / cave / arch / stack / stump.
The command is “explain”, so your answer should provide a reasoned account of how processes of coastal erosion (and weathering where appropriate) lead to the formation of the landform.
Example – Stack
Waves attack a weakness in the headland, such as a joint in sedimentary rock such as chalk. Hydraulic action means air within the crack becomes compressed by wave action and widens the crack as it escapes. Weathering processes such as salt crystallisation also enlarge cracks. Continued hydraulic action and abrasion, where transported material wears against the cliff, further enlarge the crack leading to the formation of a cave. The cave increases in size as refracted waves concentrate their energy on its sides, further enlarging the cave until it cuts breaches the headland to form an arch. Over time, the arch’s roof is weakened by weathering processes such as freeze-thaw and chemical weathering from slightly acidic rain. Eventually, it will collapse under its weight, leaving a column of rock known as a stack.
AO1 – 2 marks
AO2 – 2 marks