| A | B |
|---|
| Petrifiied | Where minerals in bones are replaced by rock hard silica |
| Carbonaceous Film | Where heat and pressure leave a thin film of carbon on a rock surface that was in contact with a fossil. |
| Original Remains | Where actual parts of the organism are preserved as a fossil. |
| Trace Fossils | Evidence of past animal activity but no part of the animal remains (burrows, worm holes, footprints). |
| Mould | Hollow cavity left in a rock where an organism has dissolved. |
| Cast | Sediments and minerals form a copy of the original organism when they fill a mould in rock. |
| Principle of Superposition | In undisturbed layers of rock, the oldest rock is on the bottom while the younger layers are on top. |
| Strata | Layers of sedimentary rock. |
| Relative Dating | Dating of rocks by comparing their location in the strata. |
| Index Fossil | A widespread fossil that gives a good indication of the age of rock that it was found in. |
| Half-Life Uranium | The time it takes for the parent material to change into the daughter material (4.5 billion years) |
| Half-Life Carbon 14 | The time it takes for the parent material to turn into the daughter material (5730 years) |
| Geologic Time Scale | The division of Earth's history onto smaller units based on the appearance of different life forms. |
| Radiocarbon Dating | Uses the half-life of carbon 14 to determine the age of fossils, bones, and wood. |
| Radiometric Dating | The use of uranium to dtermine the abslolute age of rock. |
| Eons | Largest divisions in the geologic time scale. |
| Eras | 2nd largest divisions in the geologic time scale. |
| Periods | Smallest divisions in the geologic time scale. |
| Petroleum | Naturally occuring mixture of hydrocarbons such as coal, bitumen, oil, and gas. |
| Fossil Fuels | Created from decomposed and fossilized plants and animals in solid, liquid, or gas form (coal, oil, natural gas) |
| Oil | Usually formed from water-based plants and animals. |
| Coal | Formed from land-based plants and animals. |
| Natural Gas | Formed form water or land based plants and animals. |
| Bitumen | Heaviest, solid form of petroleum that is mined using shovels and truks or separated from underground oil sands using steam. |
