| Question | Answer |
| Stensens 5 principals? | Superposition, horizontality, lateral continuity, intrusive relationships, included fragments |
| Smiths Principal? | faunal succession |
| Def. superposition | Younger layers of sed. rocks are depositited at the top. |
| Def horizontality | If rock layers are inclined they have titled afterwards |
| def lateral continuity | sedimentary rocks form extensive sheets |
| def intrusive relationships | When igneous rocks cut through layers of sedimentary rocks, the sed rocks must have been present |
| def included fragments | If fragments of a rock are found in a a larger rock, it is said that the fragmented rock was formed first |
| def faunal succession | sed. rocks of a particular age have different fossils to sed. rocks of a different age, due to the changing biosphere |
| 3 Major Eons? | Phanerozoic 0 - 0.5 Ba, Proterozoic .5 - 2.5 Ba, Archaoezoic 2.5 - 4 Ba |
| 3 Eras of the Phanerozic? | Cenozoic Mesozoic Palaeozoic |
| P C D S O C | Permian, Carboniferous, Devonian, Silurian, Ordovician, Cambrian |
| Who named P C D S O C? | Sedgewick and Murchison |
