weathering
Weathering
Weathering is the breaking down of Earth’s rocks, soil and minerals through direct contact with the planet’s atmosphere. Weathering occurs in situ or “with no movement” and thus should not be confused with erosion, which involves the movement of rock and minerals by agents such as water, ice, wind and gravity.
In addition, weathering is the effect of atmospheric exposure to man-made structures and materials.
Two important classification of weathering processes exist – physical and chemical weathering. Mechanical or physical weathering involves the breakdown of rocks and soils through direct contact with atmospheric condition, such as heat, water, ice and pressure. The second classification, chemical weathering, involves the direct effect of atmospheric chemicals or biological produced chemicals in the breakdown of rocks, soils and minerals.
The materials left over after the rock breaks down combined with organic material creates soil. The mineral content of the soil is determined by the parent materials, thus a soil derived from a single rock type can often be deficient in one or more minerals for good fertility, while a soil weathered from a mix of rock types (as in glacial, Aeolian or alluvial sediments )often makes more fertile soil.
Physical Weathering:
Physical weathering is the class of processes that causes the disintegration of rocks without chemical change. The primary process in physical weathering is abrasion (the process by which clasts and other particles are reduced in size).
However, chemical and physical weathering often go hand in hand. For example, cracks exploited by physical chemical action at mineral in cracks can aid the disintegration process.
Another type of exfoliation occurs where boulders are spheroidally weathered. These boulders are rounded by concentric shells of rock spalling off, similar to the way shells may be removed from an onion. The outer shells are formed by chemical weathering of certain minerals to a
Weathering is the breaking down of Earth’s rocks, soil and minerals through direct contact with the planet’s atmosphere. Weathering occurs in situ or “with no movement” and thus should not be confused with erosion, which involves the movement of rock and minerals by agents such as water, ice, wind and gravity.
In addition, weathering is the effect of atmospheric exposure to man-made structures and materials.
Two important classification of weathering processes exist – physical and chemical weathering. Mechanical or physical weathering involves the breakdown of rocks and soils through direct contact with atmospheric condition, such as heat, water, ice and pressure. The second classification, chemical weathering, involves the direct effect of atmospheric chemicals or biological produced chemicals in the breakdown of rocks, soils and minerals.
The materials left over after the rock breaks down combined with organic material creates soil. The mineral content of the soil is determined by the parent materials, thus a soil derived from a single rock type can often be deficient in one or more minerals for good fertility, while a soil weathered from a mix of rock types (as in glacial, Aeolian or alluvial sediments )often makes more fertile soil.
Physical Weathering:
Physical weathering is the class of processes that causes the disintegration of rocks without chemical change. The primary process in physical weathering is abrasion (the process by which clasts and other particles are reduced in size).
However, chemical and physical weathering often go hand in hand. For example, cracks exploited by physical chemical action at mineral in cracks can aid the disintegration process.
Another type of exfoliation occurs where boulders are spheroidally weathered. These boulders are rounded by concentric shells of rock spalling off, similar to the way shells may be removed from an onion. The outer shells are formed by chemical weathering of certain minerals to a