MAKING YES TOR

PART 1: Granite forms underground. The hot, solid rock cools and contracts and as it does so, forms into joints (vertical fractures). PART 2: The softer slate and sandstone around the granite erodes away, leaving a tower of the much harder rock.

PART 3: As the tor becomes exposed and the weight of the ground above it vanishes, it begins to expand upwards forming horizontal joints. Freezethaw action and weathering exacerbate the joints and small pieces of rock (clitter) fall away.