BioScience Dictionary

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Found Clay 19 times.

Displaying results 1 to 10.

1. Alfisols
Soils having significantly more clay in the B-horizon than in the A-horizon and high base status.

2. Aqualfs
Soils with an aquic or peraquic moisture regime and having clay accumulating in the B-horizon ; wet alfisol s.

3. Aquifer
* A subsurface layer of rock permeable by water. Although gravel, sand, sandstone and limestone are the best conveyers of water, the bulk of the earth's rock is composed of clay, shale and crystalline. * A saturated permeable material (often sand, gravel, sandstone or limestone) that contains or carries groundwater. * An underground, water-bearing layer of earth, porous rock, sand, or gravel, through which water can seep or be held in natural storage. Aquifers generally hold sufficient water to be used as a water supply.

4. Clay
* Particles in siliciclastic sediment that are smaller than 0.0039 millimeters in size, according to the Udden-Wentworth scale . clay and silt are collectively classified as mud . * A collective term for a large group of minerals that are found in great abundance in extremely fine-grained sediments or sedimentary rocks (i.e. shales).

5. Clay
Substrate (soil) particles generally smaller than 0.004 mm in diameter.

6. Detritus
The mineral burden of a stream, ranging from the finest clays to the largest boulders.

7. Fine sediment
Sediment with particle sizes of 2.0 mm and less, including sand, silt and clay. (Compare coarse sediment .)

8. Fines
Small particles of soils (e.g., silt or clay).

9. Histic epipedon
An 8- to 16-inch soil layer at or near the surface that is saturated for 30 consecutive days or more during the growing season in most years and contains a minimum of 20 percent organic matter when no clay is present or a minimum of 30 percent organic matter when 60 percent or more clay is present; generally a thin horizon of peat or muck if the soil has not been plowed.

10. Loess
An extremely fertile, yellowish, fine loamy soil of wind-deposited silt , often composed of the following mineral components: quartz, feldspar, horneblende, mica, and clay minerals. The silt is blown in from dry, arid places and have glacial origins. Thick deposits of loess are found on the east side of the Mississippi and Illinois rivers, and hill prairies occur on some of these deposits. The loess carried down from the highlands north of the Tibetan plateau to the North China Plain by the Yellow River (so named because of its color due to the loess) played an important role in the development of ancient Chinese civilization.

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