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science chapter 10
flashcards chapter 10 lesson 1, 2 and 3
Term | Definition |
---|---|
fossils | the preserved remains or evidence of ancient living things |
catastrophism | the idea that conditions and organisms on Earth change in quick, violent events |
uniformitarianism | states that geologic processes that occur today are similar to those that have ocurred 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 a mold of the organism is filed with sediment or mineral deposits |
trace fossil | the preserved evidence of the activity of an organism |
paleontologists | scientists who studies 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 that becomes part of a new rlock |
unconformity | a surface where rock has eroded away, producting a break, or gap, in the rock record |
correlation | matching rocks and fossils from separate locations |
index fossils | represent species that existed on Earth for a short length of time, were abundant, and inhabited many locations |
absolute age | the numerical age, in years, of a rock or object |
isotopes | are atoms of the same element that have different numbers of neutrons |
radioactive decay | the process in which an unstble 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 |