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Rocks break down into smaller pieces through weathering. Rocks and sediment grinding against each other wear away surfaces. This type of weathering is called abrasion, and it happens as wind and water rush over rocks. The rocks become smoother as rough and jagged edges break off. In this activity,...
Grade Level   3 4 5 6
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2
Sinkholes are natural depressions in the land caused when limestone and soils dissolve. They form when groundwater removes rock underground. They can form by slow gradual sinking or by sudden collapse of an underlying hole. Sinkholes are common in about one quarter of the U.S. You can usually...
Grade Level   6 7 8 9 10
Classroom Activities Curricula and Instruction
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