| A | B |
|---|
| basalt, obsidian, pumice | volcanic rocks |
| on the outside of the volcano | lava |
| inside the volcano | magma |
| magma that cools slowly | becomes plutonic rock |
| metamorphic rocks are either | igneous or sedimentary in origin |
| Fractures | cracks in the body of the rock |
| dykes form in rock fractures | when magma is being squeeze upwards |
| Strata are common in | sedimentary rocks |
| Any feature that disturbs a rock | is always younger than the rock itself |
| Olenullus is an example of an | index fossil |
| a paleontologist studies | fossils |
| arthropods have | jointed bodies and limbs |
| The Standard Geological Column | an imaginary collection of index fossilsa |
| radiometric dating is premised | on a half-life concept |
| The Law of Superposition | the oldest undisturbed rock layer is found at the bottom |
| The decay rate of a radioactive isotope | is based on its half-life |
