Physical Weathering, Erosion and Mass Wasting - Essay Example

Organisms, water and air may be needed for weathering to occur. Weathering happens without motion which separates it from another geological process called erosion. Erosion involves motion wherein various agents like water, wind and gravity brings the soil particles from one place to another (Campbell and Claridge 99). Weathering may be done in two ways: chemical weathering and physical weathering. Chemical weathering requires the interaction between the atoms and molecules of air, water and other chemical substances to breakdown the rock into finer particles.

On the other hand, physical weathering needs the heat, ice, water and pressure to mechanically breakdown the rocks without any chemical reactions involved (Denecke and Carr 433). After weathering, the rock particles mix with the organic matter on the ground to form soil. The minerals found on the soil depend upon the source materials which are the rocks. The soil coming from one type of source material may be deficient in other kinds of minerals which are required for healthy plants to grow (Campbell and Claridge 92).

Usually, the broken sedimentary rocks are fertile soil because of the rich organic materials they contain. Many of the landforms contain fertile soil because weathering is accompanied by erosion and deposition (Denecke and Carr 621). Big rocks are usually broken down into smaller rocks by mechanical weathering or physical weathering first. Afterwards, chemical weathering may occur due to the chemical substances that are exposed after the physical weathering (Craghan 161). That is how physical weathering is so important.

There are many kinds of mechanical weathering: abrasion, frost weathering, water weathering, thermal expansion, action of organisms, plant root growth, crystallization and pressure release (Schaetzl and Anderson 227). Abrasion occurs when the wind blows some rough rock fragments and those particles grind the stones and pebbles through fast action (741). On the other hand, frost weathering occurs when low temperature exists and water turns to ice. The water inside the cracks of rocks will repeatedly expand when it freezes causing the rocks to break (238).

Water weathering is different as it does not involve very low temperature. As water passes by the cracks of the rocks, it washes the minerals causing the stones to split into fragments (232). Thermal expansion occurs due to the changes in temperature and affected by the heat of the sun causing the rocks to repeatedly contract and expands in various levels until they become fragments. The thermal stress causes the binding agent in the rocks to weaken that leads to particle separation. The big difference between the temperatures of day and night causes incredible stress to the rocks giving them continuous contraction and expansion until they break into pieces (Campbell and Claridge 110).

The action of organisms like elephants stepping on the rocks cause stress that breaks the rocks into finer particles (94). Plant root growth leads to physical separation of rock particles as the roots push through the cracks as they grow (92). Crystallization occurs as an event of physical weathering in dry environments when water vapor is trapped and form crystals in dissolved minerals inside the rocks. As those crystals form and increase in size, the rocks expand causing them to slowly crack until they disintegrate (100).

For pressure release, it happens when the top rocks are