Jurassic Coast Flashcards
Where is the Jurassic Coast?
Coast of Dorset and East Devon
Where does the name ‘Jurassic’ come from?
- From the age of the rocks
- From the Triassic, Jurassic and cretaceous period
- Spanning 185 million years
What is the coastline made up of?
- Alternating layers of sedimentary rock
- Which is why there is distinctive landscapes along the coast
Triassic period (250-200 million years ago)
- Rocks were formed in desert conditions
- Rivers flowing through the desert deposited thick layers of sediment
- Rocks laid down in this period
Jurassic period (200-140 million years ago)
- Sea levels rose flooding the desert
- Sea life flourished in tropical seas
- Thick layers of sandstone, clay and limestone were deposited
Cretaceous period (140-65 million years ago)
- The sea level dropped
- New rocks were formed in swamps and lagoons
- Then earth movements tilted the rocks and the layers were eroded
- Then sea covered the land again depositing more clay, sandstone and chalk
Quaternary period (2.6 million years ago to the present)
- Erosion created hills and valleys in the landscape
- Ice ages and changes in sea level took place
- The last ice age ended 10,000 years ago
- So sea levels rose to create the modern coastline
When and what was the Winter storm?
- 5th February 2014
- A huge storm battered the Devon and Dorset coast
What was the biggest impact from the winter storm?
The damage caused to the main railway line from Exeter to Plymouth that runs along the sea wall at Dawlish
What happened to the main railway line?
- The track was left hanging in mid air
- The line had to be closed for 2 months for emergency repairs
What other places were affected by the winter storm?
- Portland Bill: buildings were damaged
- West Bay: rock falls from the cliff so the coast retreated
- Lyme Regis: pounded by waves but had defences
What makes up the West Bay?
- Alternating layers of soft sandstone and harder sandy limestone
- The cliffs can be easily eroded
What are the impacts of climate change?
Hard engineering
Soft engineering