1 2 3 4 This is a cave (‘Stair Hole’). This is an arch (‘Durdle Door’). This is a stack (Old Harry’s Rocks). These are stumps .
Caves, arches, stacks and stumps 1. The waves erode FAULTS (cracks) in the headland. 2. The waves eventually erode through the headland to form an ARCH . 3. The arch becomes unsupported and collapses to form a STACK . 4. A STUMP is formed from the collapsed stack. C D B A Match the image with the most appropriate label. 1 2 3 4
If these photos were taken of one headland over time, which of these landforms would be the first to be formed?
Exposed lines of weakness in ______ allow Hydraulic Action to form _____small along the base of the cliff. Over time the cave will continue to grow through _______ ______ and meet another cave on the other side of the headland forming a small ______. ______ will continue and undercut the base of the arch until it eventually falls due to lack of support and _______. This leaves behind a stack which will eventually collapse due to ___________and gravity to leave a _____. erosion stump undercutting gravity caves Hydraulic Action arch cliffs
Stack : an isolated pillar of rock detached from a headland by wave erosion Stages : Joints Cave Arch Stack Needle Stump Processes : Hydraulic action Corrasion/abrasion Attrition Corrosion/solution Also : Weathering Mass movement Examples : Needles (Isle of Wight) Examples : Old Harry Rocks (Jurassic Coast) The Needles (Isle of Wight Deil’s Heid (Arbroath)
Image courtesy of Andrew Stacey www.stacey.peak-media.co.uk Wave-cut platform : a sloping rocky shelf found at the foot of a retreating cliff and exposed at low tide. This is Broad Bench in Kimmeridge Bay on the Jurassic Coast Processes : Hydraulic action Corrasion Undercutting Rockfall headland Words to use: Wave-cut notch abrasion Retreating cliff