Geology walks along the West Cornwall coast

A World Heritage Site and colliding continents

If you’re looking for a walk along the West Cornwall coast that takes you past fascinating geological features, you’ve come to the right place.

The Cornish Mining World Heritage Site

The rocks of west Cornwall contain tin, copper and several other valuable minerals. These result from the formation of the granite masses of South West England. As magma cooled to form granite outcrops of Dartmoor, Bodmin Moor and the moors of West Penwith, 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.

These minerals have been mined from the Bronze Age until comparatively recently, but it was the development here of deep mining techniques from 1700 onwards that have changed our world. It provided essential raw materials to feed the Industrial Revolution in Britain, and pioneered technological developments that helped shape the society we live in today. For example, Richard Trevithick’s advances in steam engine technology – originally motivated by the need to pump water out of mines – ultimately enabled the development of steam trains, changing the world forever through the mass movement of people and goods.

This and other new engineering solutions and inventions developed here were exported to mining regions across the world – including Australia, the Americas and South Africa – playing a key role in the growth of an international capitalist economy. There are at least 175 places, across six continents, where Cornish mine workers took their skills, technology and traditions; a truly global heritage.

In recognition of this, six areas adjacent to the Coast Path are now part of the Cornish and West Devon Mining World Heritage Site – the St Agnes Mining District, Portreath Harbour, the ports of Hayle and Charlestown, the St Just Mining District and Trewavas.

The iconic ruined engine houses found along the cliffs fit in to the landscape, and it is fascinating to discover more about the lives of the miners. One of the best places for this is the mining museum at Geevor, where you can take a tour underground and nearby Levant with it's working Beam engine

The Lizard - Serpentine and other curiosities

On the Lizard peninsula, south 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.