Rainbow Rocks


Rain pounds the ground. Streams turn into raging rivers. Floods race through a valley in ancient China. Water isn’t the only thing on the move. So


are sand, dirt, and rocks. As the water rushes over them, it picks them up and moves them. T e water swirls specks of sand and mud. It


tumbles pebbles. It pushes big boulders. T is movement is called erosion. Eventually, the water slows. T e sand, mud,


and rocks fall through the water. Some of them settle on the bottom of lakes. Over time, more and more sand and rocks


pile up. T eir weight presses down. All this pressure glues the pieces together. T ey slowly turn into layers of new rock. Sand turns into rough kind of rock called sandstone. Mud becomes smooth mudstone. T e pebbles make an extra bumpy kind of rock.


T ese layers of rock remain hidden for a


long time. T en something happens. Giant chunks of Earth’s crust suddenly shiſt . T e ground shakes. It heaves and buckles. In places, the crust rises. It pushes the


hidden layers of rock upward. T e buried rocks rise higher and higher. Eventually, they form mountains with many jagged peaks. Rain then pelts the rocks. Ice cracks them.


Sand whipped by winds rubs them. T ese forces break the rocks into smaller and smaller pieces. T is process is called weathering. T en many of these same forces carry the bits and pieces away. Today, in a desert in western China, the


mountains are gone. Wind and water have sculpted them into wavy hills. Iron streaks the rock red. Other streaks of blue, gray, and gold make these rocks look like rainbow rocks.


MARCH 2013 13


Page 1  |  Page 2  |  Page 3  |  Page 4  |  Page 5  |  Page 6  |  Page 7  |  Page 8  |  Page 9  |  Page 10  |  Page 11  |  Page 12  |  Page 13  |  Page 14  |  Page 15  |  Page 16  |  Page 17  |  Page 18  |  Page 19  |  Page 20  |  Page 21  |  Page 22  |  Page 23  |  Page 24