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Flashcards in Jurassic coast line Deck (13)
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Where is the Jurassic coastline?

Between Orcombe Point in East Devon and Studland Bay in Dorset


Describe Purbeck rock beds

- made of limestone and mud
- dating back 147 million years
- borders the Jurassic and Cretaceous
- deposited in shallow, low-lying salty fresh water lagoons during fluctuating sea levels


Describe the Wealden rock beds

- made of sandstone
- dating from 140 million years ago (Cretaceous)
- deposited in fresh water rivers and lakes


Describe the greensand beds

- made of sandstone
- dating back 125 million years
- deposited in shallow, turbulant sea


Describe the Portland stone beds

- limestone
- 150 million years
- deposited in shallow, calm sea


Describe the chalk cliffs

- limestone
- 97 million years
- deposited very slowly in clear, shallow sea


How did Lulworth Cove form?

Purbeck limestone gradually eroded then rapidly eroded the cliffs behind


How did Kimmeridge Bay form?

Cliff recession happens faster because they consist of unconsolidated clays


How did Lulworth Crumple form?

Limestone and shale strata folded due to tectonic movements thirty million years ago when the African and European plates collided


What is Stair Hole?

A cove


How did Durdle Door form?

Marine erosion on vertical layers of rock


How did Warbarrow Bay form?

Less resistant wealden clay eroded to expose the chalk behind which forms the cliffs


How did the Foreland form?

Sedimentary chalk headland south of studland, erosive processes occurred to form stacks and stumps (Old Harry and Old Harry's Wife)