Weathering breaks down and loosens the surface minerals of rock. Hence, the broken rocks are transported to another place where it decomposes and forms soil. Therefore weathering is important for soil formation. Mechanical/physical weathering physical disintegration of a rock into smaller fragments, each with the same properties as the original. Occurs mainly by temperature and pressure changes and chemical weathering process by which the internal structure of a mineral is altered by the addition or removal of elements.

Mechanical/physical weathering physical disintegration of a rock into smaller fragments, each with the same properties as the original and occurs mainly by temperature and pressure changes. Chemical weathering process by which the internal structure of a mineral is altered by the addition or removal of elements. Physical, or mechanical, weathering happens when rock is broken through the force of another substance on the rock such as ice, running water, wind, rapid heating/cooling, or plant growth. Chemical weathering occurs when reactions between rock and another substance dissolve the rock, causing parts of it to fall away. Soil organic matter affects chemical, physical, and biological properties and processes in soil. The weathering of the parent material by water determines, to a large extent, the chemical composition of the soil which has ultimately been produced. Some chemicals are leached* into the lower soil layers where they accumulate. Other chemicals, more insoluble, are left in the upper layers of the soil. Weathering breaks down and loosens the surface minerals of rock. Hence, the broken rocks are transported to another place where it decomposes and forms soil. Therefore weathering is important for soil formation.