Unit 3 Vocabulary

the breaking down of rocks, soil, and minerals as well as wood and artificial materials through contact with the Earth's atmosphere, water, and biological organisms.

• erosion

• weathering

• humus

• ice wedging

the gradual destruction and removal of rock or soil in a particular area by rivers, the sea, or the weather.

• erosion

• topsoil

• weathering

• deposition

The process of weathering by which frost action, salt-crystal growth, absorption of water, and other physical processes break down a rock to fragments, involving no chemical change.

• erosion

• chemical weathering

• mechanical weathering

• deposition

The process of weathering by which chemical reactions transform rocks and minerals into new chemical combinations that are stable under conditions prevailing at or near the Earth's surface

• permeable

• decomposer

• mechanical weathering

• chemical weathering

a form of mechanical weathering or physical weathering in which cracks in rock or other surfaces fill with water, freeze and expand, causing the cracks to enlarge and eventually break.

• ice wedging

• humus

• weathering

• compaction

a measure of the ability of a porous material (often, a rock or an unconsolidated material) to allow fluids to pass through it.

• loam

• permeable

• bedrock

• subsoil

the upper layer of earth in which plants grow, a black or dark brown material typically consisting of a mixture of organic remains, clay, and rock particles.

• humus

• glacier

• soil

• extrusive rock

the organic component of soil, formed by the decomposition of leaves and other plant material by soil microorganisms.

• decomposer

• igneous rock

• fossil

• humus

solid rock underlying loose deposits such as soil or alluvium.

• bedrock

• soil

• loam

• subsoil

a rich, friable soil containing a relatively equal mixture of sand and silt and a somewhat smaller proportion of clay.

• loam

• glacier

• humus

• sedimentary rock