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Weathering

Rates Of Weathering

The rate at which rocks disintegrate depends both on the type of rock involved and the external forces to which the rock is exposed. As an example, sandstone tends to weather rather easily, while granite is quite resistant to weathering. The presence of moisture, high temperatures, large temperature variations, and air movement also tend to increase the rate at which weathering takes place. Human activities can also affect the rate of weathering. For example, large quantities of gaseous oxides are produced by electrical power generating plants. When these oxides react with water vapor in the air, they form "acid rain." When acid rain falls to the earth's surface, it may attack rocky materials in much the same way that natural acids like carbonic acid do.


Resources

Books

Hamblin, W.K., and E.H. Christiansen. Earth's Dynamic Systems. 9th ed. Upper Saddle River: Prentice Hall, 2001.

Skinner, Brian J., and Stephen C. Porter. The Dynamic Earth: An Introduction to Physical Geology. 4th ed. John Wiley & Sons, 2000.


David E. Newton

KEY TERMS

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Abrasion

—The mechanism by which one material rubs against another material, sometimes producing weathering in the process.

Chemical reaction

—Any change that takes place in which one substance is changed into one or more new substances.

Exfoliation

—The process by which skinlike layers form on the outer surface of a rock and, in some cases, eventually peel off.

Oxidation

—The chemical reaction by which a substance reacts with oxygen.

Additional topics

Science EncyclopediaScience & Philosophy: Verbena Family (Verbenaceae) - Tropical Hardwoods In The Verbena Family to WelfarismWeathering - Physical (mechanical) Weathering, Temperature And Moisture, Chemical Weathering, Rates Of Weathering - Biological weathering