| A | B |
|---|
| soil | loose rock fragments and clay derived from weathered rock mixed with organic material |
| permeability | ability of rock or sediment to let water or other liquids pass through it |
| weathering | the breakdown of rock into smaller and smaller pieces |
| mechanical weathering | breakdown of rock by physical means (ice, wind, water, gravity, plants, animals) |
| abrasion | action of rocks and sediment grinding against each other and wearing away exposed surfaces |
| chemical weathering | chemical breakdown of rocks and minerals into new substances due to weak acids, water, air, and soil |
| bedrock | layer of rock beneath the soil |
| humus | very small particles of decayed plant and animal material |
| erosion | process by which wind and water transport soil and sediment from one location to another |
| deposition | process by which material is dropped or settles |
| aquifer | flow of ground water through permeable and porous rock layer |
| limestone | made of calcium carbonate, dissolves easily in water |
| stalagmite | cone-shaped dripstone features found on the floor of a cave |
| stalactite | sharp, icicle-shaped dripstone features found suspended from cave ceilings |
| sinkhole | circular depression in the surface that forms when the water table is lower that the roof of an underground cave |
