Jackson, Ian. Northumberland Rocks — 50 extraordinary rocky places that tell the story of the Northumberland landscape. Newcastle upon Tyne : Northern Heritage, 2021.
The richly illustrated and accessible book series of Northumberland, Cumbria and Durham Rocks are available to purchase from Northern Heritage.
Theme: Volcanoes and molten rock
At the head of the Breamish Valley. Follow the road as far as Hartside Farm. The walk to the Spout is a 5 km round trip
Linhope Spout is a spectacular 18 metre waterfall cascading over Cheviot granite rocks. The granite is 400 million years old and was formed in the Devonian Period.
The Cheviot Granite was once molten rock, deep in the Earth, with a temperature of more than 1200 degrees. It was so hot that it baked the surrounding volcanic rocks. Such a large volume of molten magma and at such great depths cools and solidifies slowly. This allows the minerals within the magma (quartz, feldspar and biotite) to form large interlocking crystals that can be seen by the naked eye. The granite is over 60 square kilometres at the ground surface but at a depth of 4 kilometres it is over 300 square kilometres in area. It was once investigated as a possible deep source of geothermal energy.
Ash, elder and birch grow by the waterfall, with willow warblers. The Spout has abundant mosses, great wood rush and opposite-leaved golden saxifrage; drier ground has common dog violet.