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 |