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EOG Geologic Time
vocabulary for 8th science EOG
Term | Definition |
---|---|
fossil | preserved remains or traces of an organism that lived in the past |
trace fossil | forms when the mud or sand hardens to stone where a footprint, trail or burrow of an organism was left behind |
geologic time scale | record of the major events and diversity of life forms present in Earth's history |
relative dating | tells the age of one object compared to the age of another object |
superposition | for undisturbed layers of rock, the oldest layer is at the bottom and the layers become younger as you go up |
index fossil | fossil used to date rock layers |
radiometric dating | uses the amount of radioactive materials in rock to determine the exact age of an object |
fault | break in Earth's crust that is formed due to the movement of rock on either side |
plate tectonics | movement of Earth's plates continually change the shape of Earth's crust |
continental drift | theory that Earth's continents were once together, broke apart, and drifted to their current locations |
subduction | forcing of one plate beneath another |