The sediment comes from eroded rocks carried there by rivers or ice ... Slate is dark grey/green in colour and can be split into thin layers for use as roofing material. Marble is white or ...

The Eye of the Sahara is made up of layers of rock that have been exposed by erosion. The outer rings consist of harder rock, while the inner layers eroded more quickly, creating its distinctive ...

Sure enough, they found the jumbled deposits near the top of some hills contain rocks that have been eroded from much deeper layers and somehow carried up to the top of the hill. “You can tell ...

Thousands of hills and mounds on Mars have been found to contain layers of clay minerals ... and mesas in desert areas, where rock formations have been eroded by the wind for millions of years.