Chapter 10 Weathering and Soil Formation

Oxidation

a chemical reaction in which an element combines with oxygen to form an oxide

Soil

a loose mixture of small mineral fragments and organic materials

acid precitiation

rain, sleet, or snow that contains a high concentration of acids

Parent Rock

rock that is the source of soil

soil structure

the arrangement of soil particles

Weathering

the breakdown of rock into smaller and smaller pieces by mechanical or chemical means.

Mechanical Weathering

the breakdown of rock into smaller pieces by physical means

Chemical Weathering

the chemical breakdown of rocks and minerals into new substances

Abrasion

the grinding and wearing down of rock by other rock or sand particals

Bedrock

the layer of rock beneath soil

Leaching

the process by which rainwater dissolves and carries away the minerals and nutrients in topsoil

Differential Weathering

the process by which softer, less weather-resistant rocks wear away, leaving harder, more weather-resistant rocks behind

Erosion

the removal and transports of material by wind, water, or ice

soil texture

the soil quality that is based on the proportions of soil particles

Topsoil

the top layer of soil that genrally contains humus

Soil Conservation

the various methods by which humans take care of the soil

Humus

very small particals of decayed plant and animal materials in soil