Components, rocks, soil substances

Mineral A naturally occurring and well-crystallized inorganic and nonbiological solid substance. Minerals are major components of most rocks, sediments, and soils. 

In this chapter, the relationship of geological origins and interfacial properties of bentonite clay will be reviewed first. Then we will discuss the migration of water-soluble substances in rocks and soil, and the effect of sorption on the migration. A linear model will be derived by which the quantity of ion sorbed on rocks can be estimated when the mineral composition and sorption parameters of the mineral components are known. Surface acid-base properties of soils will be discussed, and the sorption of an anion (cyanide ion) will be shown on different soils and sediments. 

Some components, for example, Fe(II), are oxidized by air to Fe(lll). Water will dissolve the chemical substances in rocks. The presence of carbon dioxide usually helps dissolution process, because it makes water acidic. The fragmented and/or dissolved material may be redeposited on land, which forms soil. The fragmented and dissolved material may be carried to the ocean and eventually deposited and compacted at the bottom, which forms sedimentary rocks. 

The weathering of parent rocks and minerals to form the inorganic soil components results ultimately in the formation of inorganic colloids. These colloids are repositories of water and plant nutrients, which may be made available to plants as needed. Inorganic soil colloids often absorb toxic substances in soil, thus playing a role in detoxification of substances that otherwise would harm plants. The abundance and nature of inorganic colloidal material in soil are obviously important factors in determining soil productivity. 

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