Weathering

Weathering is a term that is used to describe the breakdown of solid rock into particles of sediment such as boulders, sand, silt, and mud, as well as ions that are dissolved in water. Two types of weathering processes are recognized physical weathering and chemical weathering. Physical weathering refers specifically to the reduction of a volume of rock and or individual particles of sediment into progressively smaller and smaller sedimentary particles through mechanical processes. These mechanical processes include fracturing and disintegration by freezing and thawing, transport by glaciers or even rolling along a shoreline by waves. Chemical weathering on the other hand refers to the chemical breakdown of minerals in rocks and the production of new minerals from the dissolved ions. Most chemical reactions proceed fastest when temperatures are elevated and also when there is an abundance of water. In warm wet climates, chemical weathering proceeds fastest, so one would expect that the same rock would chemically weather much faster in a tropical rain forest rather than on an arctic tundra. It is also important to note that because of the nature of chemical reactions in warm humid climates, there is a more significant production of very fine sediment.