rock climbing courses

Geology for climbers - Kent and Sussex

The climbing courses in this area are run on the fantastic sandstone cliffs. Although these rocks used mainly used for rock climbing, this area is also famous, geologically for the discovery of the first dinosaur and the hoax of the Piltdown Man.

Although the area can be traced back to 350 to 300 million years ago (mya) in the Carboniferous the cliffs we are interested in were made 150 to 65 mya during the Cretaceous period

The Purbeck Beds are the oldest rocks in the area, which can be found around the south coast. The purbect bed are mainly found in Swanage and Dorest and have little impact on the cliff of the Wealden Basin.

About 135 million years ago there was a change in the type of rocks laid down in this area. During this time a shallow sea covered most of Kent and Sussex. Sediment was washed down by rain and rivers and deposited under the sea. Large quantities of sand was deposited in the area and it was this deposition that caused the famous sandstone cliffs of Kent and Sussex. More layers of sediment and a layer of Chalk then covered the sand.

Over mainly millions of years the sand will have been subjected to pressure and slowly dired out, this will have caused the rocks to harden

When the African and Indian plates collided with each other around 50 million years ago there was a ripple effect in the earths crust. This caused an upheavel of the land and exposed the rocks to the wind and rain.

South East rocks

As the land became exposed to the elements, the rocks and soils started to erode again. The higher rocks were eroded more as these had more exposure to the the wind rain and ice, but there has been less erosion on the harder rocks such as the sandstone outcrops we climb on.

The outer layer of the sandstone has become very hard through a process called case hardening. This is a chemical process causing the formation of an outer crust, this crust is only a couple of millimetres thick. This is why, as climbers we need to be very careful to protect the rock when climbing. This can be done by following the Sandstone code of practice.


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