The Geology of Coverack

Stand overlooking the beach at Coverack and you may well see a party of geology students, earnestly studying the dark rocks protruding from the sand.

Walk along the beach yourself and you will experience one of the world's greatest geological rarities - the sight of what was once the boundary between the rocks of the Earth's crust and those of the lower molten mantle. This junction is known as the 'Moho' discontinuity (after Andrija Mohorovicic, who discovered that seismic waves change their velcoity as they pass from the crust into the mantle).

If you stand on the road by 'Brenda's' and look to your left, the rocks you see are predominantly made of gabbro - formed in the earth's crust. Look towards the harbour, though, and darker serpentine rocks you see here come from the mantle.

Above: The Gabbro
Right: Serpentine Rocks

Immense pressure squeezed the rocks upwards and the serpentine you see here today is a rare glimpse of a rock which, 375 million years ago was well south of the equator and in a molten state some 10 kimometres below the Earth's surface,long before the existence of the first reptiles and amphibians and long, long before the first dinosaurs and mammals.

If you are interested in finding out more about the local geology you will find books available in the local shops and also at the community reference library section at Coverack School (in the Online Centre).

For further information on Geology click on the following websites: www.geological.nildram.co.uk
www.cornwallwildlifetrust.org.uk/images/geology/rigsmap2.gif
or see our
Geology
Information Board

(2.5MB.pdf)