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Chapter10 L1-3
Term | Definition |
---|---|
fossil | The preserved remains or evidence of ancient living things. |
catastrophism | The idea that conditions and organisms on Earth change in quick, violent events. |
uniformitarianism | That geologic processes that occur today are similar to those that have occurred in the past. |
carbon film | The fossilized carbon outline of an organism or part of an organism. |
mold | The impression in a rock left by an ancient organism |
cast | A fossil copy of an organism. Made when filling a mold. |
trace fossil | Preserved evidence of activity |
paleontologist | scientists who study fossils |
Relative age | The age of rocks and geologic features compared with other rocks and features nearby, |
superposition | The principle that in undisturbed rock layers, the oldest rocks are on the bottom |
inclusion | A piece of an older rock the becomes part of a new rock |
unconformity | A surface where rock has eroded away, producing a break, or gap, in the rock record. |
correlation | Matching rocks and fossils from different locations |
index fossil | Species that existed on Earth for a short length of time, were abundant, and inhabited many locations. |
absolute age | Mean the numerical age, in years of a rock or object. |
isotope | Atoms of the same element that have different amounts of neutrons. |
radioactive decay | The process by which an unstable element naturally changes into another element that is stable |
half-life | The time required for half of the parent isotopes to decay into daughter isotopes |