Weathering is the breakdown and alteration of material near the earth's surface to products that are more in equilibrium with newly imposed physico-chemical conditions. May rocks were originally formed at high temperature, high pressure and in the absence of air and water, and a large part of weathering is a response to low temperatures, low pressures and the presence of air and water /Ollier 1975/. Weathering of the initial materials precedes soil formation in hard rocks and accompanies it in soft rocks and soil materials. It is a continuous reaction during soil development, to the point where no more reactants are available.

11 pages, 5 figures, 12 references.-- Proceedings of the 8th Meeting of the Soil Biology Section of the Hungarian Society for Soil Science, Gödöllö, 26–28 August, 1981.

Peer reviewed