Fan Rock's spectacular columns tell us that the lava cooled from the outside, then solidified, shrunk and cracked. Surface cracks grew deeper as the rock below cooled, forming prominent columns fanning out from the centre of the volcano.
In the millenia that followed, wind and water eroded the surface lava, ash and soft rock - exposing the lava plug and revealing the striking effect you can see here today.
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1. What age was it around 60 million years ago?
2. Which plate was heading North?
3. What shape are the columns?
4. What does the lava plug consist of?
5. How many other volcanos are "remnants of a fiery past"?