Discover Geology
PICTURE: Geology - often hidden, but clearly seen from the Coast Path
Geology - often hidden, but clearly seen from the Coast Path
Icon - GeologySee the Walks for Everyone pages to find descriptions of Coast Path walks which are especially good for geology. You can search for a walk that is known for its geological interest as well as by area, length and degree of difficulty.
Travel back through millions of years... Look for evidence of ancient deserts or fossil forests, track the dinosaurs on the Jurassic Coast. Follow the path across granite, serpentine, primeval seabeds and coral reefs.

As you walk the South West Coast Path you will journey across the varied geology displayed in our coastline.

Some rocks may not attract your attention while others are more noticeable. They may be particularly colourful, have unusual patterns, contain fossils or be contorted into fantastic shapes. These features are all evidence of how and where rocks were formed. As they vary in age, they provide a record of how the environment has changed over hundreds of millions of years.

The coastal geology of Dorset and East Devon is so unique and played such an important part in the development of the earth sciences that it has been designated a World Heritage Site.

Here’s a whistle-stop tour of some geological stories you will encounter along the South West Coast Path.

Links on this page:
Exmoor, North and South Devon and Cornwall - Shales, Slates and Sandstones

Photo: Folded rocks at Millock HavenThese rocks were laid down over several hundred million years when this area was part of a vast ocean basin. Sediments that were eroded from the adjacent land were deposited in the sea by rivers. Coarse sediments were laid down in deltas and shallows to eventually form sandstones, while fine particles were carried into deeper water to form mudstones and shales. Fossils of animals and plants characteristic of these different environments are found locally.

These rocks were later affected by intense heat and pressure, changing their character and distorting them into faults and folds. The Coast Path walker will see especially spectacular examples of folded rocks on the north coast between Hartland and Crackington Haven.

TOP OF PAGE

Pentire Head, North Cornwall – a submarine volcano
Photo: The volcanic promontory of the RumpsRoughly 370 million years ago the area that is now Devon and Cornwall lay under shallow seas. In places, submarine volcanoes were erupting. On the Coast Path the results are dramatically displayed at Pentire Head east of the Camel estuary. The rocks here show their origins in two ways. Between Pentire Point and the Rumps you can see what looks like a pile of rock pillows which formed as the lava skinned over as it cooled in contact with the sea. Petrified gas bubbles were trapped inside and these can be seen in some individual rock outcrops.


TOP OF PAGE
Cornwall - Minerals and Mining
Photo: The spectacular setting of a Cornish MineRuined engine houses are a common sight on the Coast Path in West Cornwall, memorials to a mining industry that flourished from the Bronze Age until comparatively recently. Six areas adjacent to the Coast Path are now part of the Cornish Mining World Heritage Site – the St Agnes Mining District, Portreath Harbour, the ports of Hayle and Charlestown, the St Just Mining District and Trewavas. To find out more, visit: www.cornish-mining.org.uk, http://whc.unesco.org/

The presence of tin, copper and several other minerals is related to the granite masses of South West England. As magma cooled to form granite, hot gases and super-heated water penetrated cracks and fissures in the surrounding rocks. The water and gases cooled and the chemical elements they contained crystallised out as mineral veins. High temperature minerals (such as tin and copper) were deposited closest to the granite, and lower temperature ones (such as zinc and lead) further away.


TOP OF PAGE
The Lizard - Serpentine and other curiosities
Photo: SerpentineSouth of a fault line between Polurrian Cove and Porthallow the Coast Path walker is walking on rocks that came from several miles below the surface of the earth some 375 million years ago. It is thought that the rocks here formed deep in the Earth’s crust and were pushed up to form the unusual rocks of the Lizard Complex. Basalt, gabbro, gneiss, schist and serpentine are some of the rocks you will encounter.

You will come across all of these as you walk the Coast Path around the edge of the Lizard. The serpentine varies from reds to greens and greys - colours that are beautifully brought out when the rocks are wet or polished. Look out for sea-washed beach pebbles and the serpentine souvenirs made and sold locally to see this effect. You will also find it where thousands of feet have polished the serpentine stones in the surface of the Coast Path and its stone stiles.

Mor on Page 2