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The view that most of earth's geological features are the result of large scale catastrophes such as floods, volcanic eruptions, etc.


The view that most of earth's geological features are the result of slow, gradual processes that have been at work for millions or even billions of years


The decayed remains of once-living creatures


Inorganic crystalline substances found naturally in the earth


The process by which rocks are broken down by the forces of nature


The process by which sediments and rock fragments are carried away by wind or rain


A surface of erosion that separates one layer of rock from another

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