![Top curves](../../../../jsp/jahia/templates/GSL/gsl_templates/img/keystage3/main_top_grad.gif)
Basalt pillow lava, Cornwall
![Basalt hand specimen](../../../../webdav/site/GSL/shared/images/education_and_careers/RockCycle/RocksAroundBritain/Basalt%20resized.jpg)
These 400 million year old pillows must also have been formed by under-water volcanic eruptions, showing that, during the Devonian Period, this part of southwest England must have been under water. Other evidence shows that Cornwall lay in deep water, whilst parts of south Devon formed shallow coral reefs with a coast further north.
Basalt pillow lavas, Clodgy Point, St Ives
![Pillow lavas, St Ives](../../../../webdav/site/GSL/shared/images/education_and_careers/RockCycle/RocksAroundBritain/St%20Ives%20Pillows%20xtrawide.jpg)
![Bottom curves](../../../../jsp/jahia/templates/GSL/gsl_templates/img/keystage3/bottom_curve.gif)