Stacks and Stumps

Gap-fill exercise
The "12" Apostles in Australia

Fill in all the gaps, then press "Check" to check your answers. Use the "Hint" button to get a free letter if an answer is giving you trouble. You can also click on the "[?]" button to get a clue. Note that you will lose points if you ask for hints or clues!
These features are formed on or headlands. Waves attack vertical lines of in the rock known as Faults. Processes such as and abrasion widen these faults into cracks and eventually the waves will penetrate deeply enough to create .

Over time, the cave will be eroded into an , accessible to the sea on both sides. Weathering will also play a role, with weathering processes such as freeze thaw and salt crystallisation and processes such as carbonation weakening the rock surrounding the cave or arch making it more susceptible to mass movement and collapse.

Finally, the erosion and weathering continues and the arch collapses leaving behind a (a vertical column of rock) . These stacks can be attacked further, and eventually the stack may collapse to leave a low lying .