click below
click below
Normal Size Small Size show me how
Unit 7
Changes to Earth's Surface
Term | Definition |
---|---|
weathering | the breaking down of rocks on Earth's surface into smaller pieces |
erosion | the process of moving sediment from one place to another |
deposition | the dropping or settling of eroded materials |
sedimentary rock | a type of rock that forms when layers of sediment are pressed together |
fossil | the remains or traces of a plant or animal that lived long ago |
mold | an impression of an organism, formed when sediment hardens around the organism |
cast | a model of an organism, formed when sediment fills a mold and hardens |
fossil fuel | fuel, such as coal, oil, natural gas, formed from the remains of once-living things |
index fossil | a fossil of a type of organism that lived in many places during a relatively short time span |
mass extinction | a period in which a large number of species become extinct |