(See related pages)
Below you will find key words and concepts that you should remember from this chapter.
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| A horizon (zone of leaching) | The top layer of soil, characterized by the downward movement of water; also called zone of leaching. (See page(s) 311) |
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| B horizon (zone of accumulation) | A soil layer characterized by the accumulation of material leached downward from the A horizon above; also called zone of accumulation. (See page(s) 311) |
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| chemical weathering | The decomposition of rock resulting from exposure to water and atmospheric gases. (See page(s) 301) |
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| C horizon | A soil layer composed of incompletely weathered parent material. (See page(s) 311) |
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| clay mineral | A hydrous aluminum-silicate that occurs as a platy grain of microscopic size with a sheet silicate structure. (See page(s) 308) |
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| differential weathering | Varying rates of weathering resulting from some rocks in an area being more resistant to weathering than others. (See page(s) 303) |
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| erosion | The physical removal of rock by an agent such as running water, glacial ice, or wind. (See page(s) 300) |
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| exfoliation | The stripping of concentric rock slabs from the outer surface of a rock mass. (See page(s) 304) |
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| exfoliation dome | A large, rounded landform developed in a massive rock, such as granite, by the process of exfoliation. (See page(s) 304) |
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| frost action | Mechanical weathering of rock by freezing water. (See page(s) 303) |
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| frost heaving | The lifting of rock or soil by the expansion of freezing water. (See page(s) 303) |
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| frost wedging | A type of frost action in which the expansion of freezing water pries a rock apart. (See page(s) 303) |
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| hematite | A type of iron oxide that has a brick-red color when powdered; Fe2O3. (See page(s) 306) |
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| laterite | Highly leached soil that forms in regions of tropical climate with high temperatures and very abundant rainfall. (See page(s) 315) |
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| limonite | A type of iron oxide that is yellowish-brown when powdered; Fe2O3·nH2O. (See page(s) 306) |
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| loam | Soil containing approximately equal amounts of sand, silt, and clay. (See page(s) 311) |
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| mechanical weathering | The physical disintegration of rock into smaller pieces. (See page(s) 301) |
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| O horizon | Dark-colored soil layer that is rich in organic material and forms just below surface vegetation. (See page(s) 311) |
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| pressure release | A significant type of mechanical weathering that causes rocks to crack when overburden is removed. (See page(s) 303) |
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| residual soil | Soil that develops directly from weathering of the rock below. (See page(s) 312) |
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| sheet joints | Cracks that develop parallel to the outer surface of a large mass of expanding rock, as pressure is released during unloading. (See page(s) 303) |
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| soil | A layer of weathered, unconsolidated material on top of bedrock; often also defined as containing organic matter and being capable of supporting plant growth. (See page(s) 310) |
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| soil horizon | Any of the layers of soil that are distinguishable by characteristic physical or chemical properties. (See page(s) 311) |
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| spheroidally weathered boulder | Rounded by weathering from an initial blocky shape. (See page(s) 301) |
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| transportation | The movement of eroded particles by agents such as rivers, waves, glaciers, or wind. (See page(s) 300) |
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| transported soil | Soil not formed from the local rock but from parent material brought in from some other region and deposited, usually by running water, wind, or glacial ice. (See page(s) 312) |
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| weathering | The group of processes that change rock at or near Earth’s surface. (See page(s) 300) |
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| E horizon | soil zone where downward movement of water removes fine-grained soil components such as clay. (See page(s) 311) |