Granite Tors start to form when magma that has intruded into the crust cools to form a batholith. The softer rock above the batholith erodes away over time leaving the batholith exposed to the elements.

While the rock is cooling it starts to contract causing cracks- these also occur when the batholith is exposed and pressure is released.

The cracks in the Granite rock are made worse by the process of freeze-thaw weathering, this is the process where water gets into the cracks in the rocks and freezes when the temperature drops, expanding by 9%, this repeated process causes the cracks in the rock to widen. This process affects the Tor more where the joints are closer together.

As this freeze-thaw weathering continues bits of Rock start to break off, the name for these pieces of rock is scree.

This type of weathering leaves the Tor with certain characteristics:

1. The joints also become visible in the Tor,

2. The Tors edges are smooth and round.

Horizontal Bedding Planes

Smooth Round Edges

Vertical Joints

Case study: Dartmoor

Dartmoor has many Tors and is a popular popular place with tourists.

Most of the Dartmoor Tors are located in the Dartmoor national park, this makes it an ideal place to visit for tourists.

Bowermans nose:

Examples of Dartmoor Tors:

Black Tor

Hay Tor Hound Tor