- 行业: Earth science
- Number of terms: 26251
- Number of blossaries: 0
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An international scientific society that fosters the transfer of knowledge and practices to sustain global soils. Based in Madison, WI, and founded in 1936, SSSA is the professional home for 6,000+ members dedicated to advancing the field of soil science. It provides information about soils in ...
(i) Recently transported and deposited material that occurs immediately superjacent to the surface horizon of a contemporaneous soil. (ii) A term used to designate disturbed or undisturbed material of any nature, consolidated or unconsolidated, that overlies a deposit of useful materials, ores, lignites, or coals, especially those deposits mined from the surface by open cuts.
Industry:Earth science
A property of soil which results from the attraction of the soil matrix for water.
Industry:Earth science
A mineral surface carrying a net electrical charge whose magnitude depends only on the structure and chemical composition of the mineral itself. Constant charge surfaces in soils usually arise from isomorphous substitution in phyllosilicate clay structures.
Industry:Earth science
(i) A broad group of textures consisting of or containing large quantities of the fine fractions, particularly of silt and clay. (Includes all sandy clay, silty clay, and clay textural classes). (ii) When used in reference to family particle-size classes in U. S. soil taxonomy, is specifically defined as having 35 to 60 percent clay.
Industry:Earth science
A layer of positive ions held so tightly to the clay surface that they migrate with the clay in an electrical field.
Industry:Earth science
A rock consisting of various minerals that have crystallized in place from magma. Crystalline rock have a well-ordered arrangement of ions, a definite chemical composition, and a regular geometrical form.
Industry:Earth science
A method that uses the timing of wave reflections to determine the properties of various materials, such as the dielectric constant of soil as an indication of water content.
Industry:Earth science
A relation between soluble sodium and soluble divalent cations which can be used to predict the exchangeable sodium fraction of soil equilibrated with a given solution. It is defined as follows, where concentrations, denoted by brackets, are expressed in mmoles per liter:
SAR = (sodium)/(calcium + magnesium)1/2
Industry:Earth science
A simple, single numerical value that expresses climatic relationships; for example, the numerical value obtained in Transeau's precipitation-evaporation ratio.
Industry:Earth science
