| A | B |
|---|
| climate | weather pattern that occurs in a particular area over many years |
| oxidation | chemical weathering process that occurs when metallic material is exposed to oxygen and water over time |
| chemical weathering | occurs when chemical reactions dissolve the minerals in rocks or change them into different minerals |
| ice wedging | mechanical weathering process that occurs when water freezes in the cracks of rocks and expands, causing the rock to break apart |
| mechanical weathering | physical process that breaks rocks apart without changing chemical makeup; can be caused by ice wedging, animals, plant roots |
| weathering | mechanical or chemical surface processes that break rocks into smaller and smaller pieces |
| soil | mixture of weathered rock, decayed organic matter, mineral fragments, water, air that can take thousands of years to develop |
| humus | dark-colored, decayed organic matter that supplies nutrients to plants and is found mainly in top soil |
| horizon | each layer in a soil profile |
| horizon A | top layer of soil |
| horizon B | middle layer of soil |
| horizon C | bottom layer of soil |
| soil profile | vertical section of soil layers, each of which is a horizon |
| litter | twigs, leaves, organic matter that help prevent erosion and hold water, may eventually be changed into humus by decomposers |
| leaching | removal of minerals that have been dissolved in water |
