Changing Rock Our next island is a jumble of rocky towers. Rain and


ice have slowly worn away the rock. T is weathering created skinny rock shapes.


We look at the bottom of the towers. We can see rocky pieces that have fallen from above. In time, weathering and erosion will wear away these towers.


River of Ice Not far away is a maze of grassy, round hills. T ey


formed in a diff erent way. Long ago, a glacier, or river of ice, fl owed over the land. T e heavy ice smoothed the land. T e ice melted. Now there are round hills.


T ese hills are one more example of how wind and water shaped these islands. Weathering and erosion are still at work! T ese islands will keep changing.


Wordwise


erosion: the process of picking up and moving pieces of rocks and other materials


glacier: a large body of ice that slowly moves across land


weathering: the process of breaking rock into smaller pieces


14 NATIONAL GEOGRAPHIC EXPLORER


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