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. <ul><li>This type of weathering leaves the Tor with certain characteristics: </li></ul><ul><li>The joints also become visible in the Tor, </li></ul><ul><li>The Tors edges are smooth and round. </li></ul>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: Here are a few of the Dartmoor Tors: Black Tor Hay Tor Hound Tor