The Earth Story
Start Bay is an amazing place to discover all about geology as the shape of the Bay means that there are many different types of rock on view!
The rocks beneath your feet help determine the shape of the land, what grows on it and how and where we live. At the coast the sea has shaped the landscape and also washed away the soil, making it easier to see how the rocks have been formed.
A rocky start
To create the interesting shapes that you can see at Strete Gate, over hundreds of millions of years, rocks were formed, compressed, folded and then weathered.
The Start Bay rocks date back 400 million years to when much of the area was under a tropical sea and nearer to the equator. Sediment eroded from the land further north settled in river beds on the coastal plain and under the sea – forming ‘sedimentary’ rocks.
A long period of mountain building followed caused by continents colliding. This folded the rocks into unusual shapes. The enormous weight piled on by the mountains compressed the rocks making them harden up and change into ‘metamorphic‘ rocks.
A changing climate
Over time, the rocks have weathered and the changing climate has also had an impact. When the climate was warmer, sea levels were higher and the breaking waves wore flat areas on the rocks called ‘wave cut platforms’ as at Hallsands, which are now above current sea levels.
Slapton Ley and Widdicombe Ley lakes were also formed by climate change. During the last ice age lots of water was locked up in ice sheets. This made the sea level fall and the coastline move 20 miles further out than it is now. When the climate warmed, the ice melted making the sea level rise. The sea returned pushing a ridge of shingle before it, which dammed a number of streams to create the lakes.
The download on the right shows the information panel which is in place in the car park at Strete Gate. It shows the locations of where to see different rocks and geological formations around the Bay.