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The Rock Cycle |
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Ch. 3 Rock Cycle Notes The wearing away of rocks is called weathering. It is a slow process. Physical weathering is the wearing away of rocks by the action of wind or moving water. A rock that gets worn by water in a stream, which has sediments in it, is an example of this. Water gets trapped in cracks of rocks, and freezes. When water freezes, it expands, which causes larger cracks. Some kinds of weathering involve changes in the minerals that make up rocks. Weathering that results in changes in minerals is called chemical weathering. An example of this is the creation of caves. The limestone gets eaten away by acid rain. Acid rain forms from smog mixed with rainwater. Biological weathering is the wearing down of rock by living things. An example of this is, a tree roots that grow under a sidewalk can cause the sidewalk to be uplifted or cracked. WEATHERING FORMS SEDIMENTS, WHICH MAKES NEW ROCKS! WHAT IS THE ROCK CYCLE? Sediments form, they go through compaction and cementation, which form sedimentary rocks. These get buried deep in the earth and get exposed to heat and pressure. It folds and becomes metamorphic rock. This gets so hot it becomes magma, and it explodes from a volcano. It is now igneous rock. This newly formed rock gets exposed to weathering, which forms sediments, and the process starts all over again! |
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