Hoodoo (geology)

Hoodoo formations are really cool looking rocks that are found in deserts and canyons. You might have seen them before - they look like tall skinny pillars with a flat rock on top.

So how did they form? Well, it all starts with the land. The ground where hoodoos are found is made up of different layers of rock and sediment that were deposited over millions of years. The top layer is usually made of a hard rock called limestone, while the bottom layers are made up of softer materials like sandstone and shale.

Over time, wind and water have eroded the softer layers of rock away, leaving behind the limestone pillars. But that's not the whole story - there's also something called frost wedging that plays a role here.

When the temperature drops below freezing, any water that's in the ground can freeze and then expand. This expansion causes cracks to form in the rock. Over time, these cracks get bigger and bigger until a large piece of rock breaks off. This is what creates the flat top that you see on hoodoos - it's the remnants of the layer of rock that used to be there before it broke off.

So there you have it - hoodoos are tall, skinny pillars of rock that were formed by erosion and frost wedging over millions of years. It's just like when you build a sandcastle at the beach and the waves come and wash it away, except on a much larger scale!