This rock recycling is a process called the rock cycle. The Earth's rocks are constantly changing. They have been slowly recycled over millions of years.This is called the rock cycle.Sedimentary ...

Beyond the mystery of what kind of life left these markings is a deeper question: what were they doing to the rock? If these ...

Strange, tiny structures have been found in the rocks around the deserts of southern Africa and the Arabian Peninsula.

Mysterious tunnels in desert rocks may be the work of unknown microbes, hinting at a hidden world inside marble and limestone ...