| A | B |
|---|
| Catastrophism | The view that most of earth's geological features are the result of large-scale catastrophes such as floods, volcanic eruptions, ect. |
| Uniformitarianism | The view that most of earth's geological features are the result of slow, gradual processes that have been at work for millions or even billions or years |
| Humus | The decayed remains of once-living creatures |
| Minerals | Inorganic crystalline substances found naturally in the earth |
| Weathering | The process by which rocks are broken down by the forces of nature |
| Erosion | The process by which sediments and rock fragments are carried away by wind or rain |
| Unconformity | A surface of erosion that separates one layer of rock from another |
| Sedimentary rock | Rock that is formed from sediments which are laid down by water or some other agent |
| Igneous rock | Rock that is formed from molten rock, which is usually called magma |
| Metamorphic rock | Rock that has undergone extreme change due to heat and pressure |
| Strata | Layers in sedimentary rock |
| Stalactite | A deposit of calcium carbonate resembling an icicle hanging down from the roof or sides of a cavern |
| Stalagmite | A deposit of calcium carbonate like an inverted stalactite formed on the floor of a cave. |
