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.