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 gigantic Yellowstone Grand Canyon, lined with volcanic rock. With all the effects of hydrothermal activity, river erosion and glacier activity this amazing formation was created ( Kiley Williams) ...

Inside these eroded mounds are layers of clay formed ... Immediately below the clay layers are older layers of rock that contain no clay; above the clay layers are younger layers of rock that ...

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.