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A Quaternary clay deposit in Estonia, laid down about 400,000 years ago. Clay is a type of fine-grained natural soil material containing clay minerals [ 1] (hydrous aluminium phyllosilicates, e.g. kaolinite, Al 2 Si 2 O 5 ( OH) 4 ). Most pure clay minerals are white or light-coloured, but natural clays show a variety of colours from impurities ...
The most common engineering classification system for soils in North America is the Unified Soil Classification System (USCS). The USCS has three major classification groups: (1) coarse-grained soils (e.g. sands and gravels ); (2) fine-grained soils (e.g. silts and clays ); and (3) highly organic soils (referred to as "peat").
The specific heat of pure water is ~ 1 calorie per gram, the specific heat of dry soil is ~ 0.2 calories per gram, hence, the specific heat of wet soil is ~ 0.2 to 1 calories per gram (0.8 to 4.2 kJ per kilogram). [90] Also, a tremendous energy (~584 cal/g or 2442 kJ/kg at 25 °C) is required to evaporate water (known as the heat of ...
Soil types by clay, silt and sand composition as used by the United States Department of Agriculture. Loam (in geology and soil science) is soil composed mostly of sand (particle size > 63 micrometres (0.0025 in)), silt (particle size > 2 micrometres (7.9 × 10 −5 in)), and a smaller amount of clay (particle size < 2 micrometres (7.9 × 10 −5 in)).
Clay minerals are hydrous aluminium phyllosilicates (e.g. kaolin, Al 2 Si 2 O 5 ( OH) 4 ), sometimes with variable amounts of iron, magnesium, alkali metals, alkaline earths, and other cations found on or near some planetary surfaces . Clay minerals form in the presence of water [ 1] and have been important to life, and many theories of ...
A soil scientist examining horizons within a soil profile. Soil science is the study of soil as a natural resource on the surface of the Earth including soil formation, classification and mapping; physical, chemical, biological, and fertility properties of soils; and these properties in relation to the use and management of soils. [ 1]
Soil texture focuses on the particles that are less than two millimeters in diameter which include sand, silt, and clay. The USDA soil taxonomy and WRB soil classification systems use 12 textural classes whereas the UK-ADAS system uses 11. [ 1] These classifications are based on the percentages of sand, silt, and clay in the soil.
Expansive clay is a clay soil that is prone to large volume changes (swelling and shrinking) that are directly related to changes in water content. [ 1] Soils with a high content of expansive minerals can form deep cracks in drier seasons or years; such soils are called vertisols. Soils with smectite clay minerals, including montmorillonite and ...