causing them to change into another type of rock. They are usually resistant to weathering and erosion and are therefore very hard-wearing. Examples of metamorphic rocks include marble ...

“Just don’t leave painted rocks in the park. What’s so hard about that?” a third responded ... the park’s acting chief of interpretation. This kind of heated banter is common on social media, but it ...

New research reveals how rock strength plays a crucial role in erosion, shaping landscapes over millions of years.

That’s the channel inside a volcano that opens up to the surface. As it cools it becomes a very hard type of igneous rock. This one first formed over 350 million years ago. Then, millions of ...