Caves, Arch, Stack and Stump

• How is a cave formed?

  Firstly, a headland is eroded by hydraulic action and abrasion. This leads to the crack widening and forming a cave.
• How is an arch formed?

  Secondly, hydraulic action and abrasion continue to erode and cuts all the way through. This forms an arch.
• How is a stack formed?

  Thirdly, the arch collapses as it becomes too heavy to support. This forms a stack.
• How is a stump formed?

  Lastly, the stack will be undercut and leave behind a stump
• What is a cave?

  Natural underground chamber.
• What is an arch?

  A curved structure.
• What is a sea stack?

  A sea stack is a vertical column of rock that remains standing after the erosion of the surrounding cliffs by the sea.
• What is a sea stump?

  Remnant of a stack