| A | B |
|---|
| model | somethng used to represent an object or idea |
| crust | outer layer of the earth |
| mantle | layer below the crust of the earth |
| core | layer below the mantle, made up of an inner and outer core |
| fossil | remains and traces of living things preserved in rocks |
| relative age | how old a rock is compared to other rocks |
| index fossil | a certain type of fossil used to help tell the relative age of the rock layer |
| absolute age | how old the rock really is |
| trilobite | common index fossil |
| fold | a bend in the rock layer |
| anticline | upward fold of a rock layer |
| syncline | downward fold of a rock layer |
| erosion | wearing away and removal of rock materials |
| fault | a break in a rock along which movement has occurred |
| normal fault | a break that occurs when rock layers are pulled in opposite directions; one side moves down in relation to the other |
| reverse fault | a break formed when pushing forces cause a rock to move up in relation to the others |
| strike-slip fault | a break caused by plate movement that causes rock layers to slide sideways in opposite directions |
