The Land and People
Is Tinto Hill a volcano? At 707 metres high Tinto hill is a well-known landmark in South Lanarkshire.
The red, hard rock called Felsite that is often used to form Lanarkshire’s roads is also found near the top of Tinto’s summit. This rock comes from deep in the earth, between 50-200 kms beneath the surface crust. At such depths the rock can melt and become like hot plastic, it’s known as magma. If there’s a weakness in the earth’s surface the magma can be pushed up and erupt on the surface to form a volcano.
Sometimes though the magma just pushes up inside the earth’s crust to form a dome, then it cools down below the surface. This is called an igneous intrusion. This is what happened to form Tinto hill, so Tinto is not a volcano it’s a felsite igneous intrusion.