Preferred Name | silt | |
Synonyms |
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Definitions |
Particulate environmental material which is primarily composed of silt particles. This definition is intentionally ambiguous to support the multiple thresholds set by different authorities. Some authorities consider this soil material that contains 80% or more silt and less than 12% clay. In the Udden-Wentworth scale (due to Krumbein), silt particles range between 0.0039 to 0.0625 mm, larger than clay but smaller than sand particles. ISO 14688 grades silts between 0.002 mm and 0.063 mm. In actuality, silt is chemically distinct from clay, and unlike clay, grains of silt are approximately the same size in all dimensions; furthermore, their size ranges overlap. Clays are formed from thin plate-shaped particles held together by electrostatic forces, so present a cohesion. According to the U.S. Department of Agriculture Soil Texture Classification system, the sand-silt distinction is made at the 0.05 mm particle size. The USDA system has been adopted by the Food and Agriculture Organization (FAO). In the Unified Soil Classification System (USCS) and the AASHTO Soil Classification system, the sand-silt distinction is made at the 0.075 mm particle size (i.e., material passing the #200 sieve). Silts and clays are distinguished mechanically by their plasticity. |
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ID |
http://purl.obolibrary.org/obo/ENVO_01000016 |
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comment |
This definition is intentionally ambiguous to support the multiple thresholds set by different authorities. Some authorities consider this soil material that contains 80% or more silt and less than 12% clay. In the Udden-Wentworth scale (due to Krumbein), silt particles range between 0.0039 to 0.0625 mm, larger than clay but smaller than sand particles. ISO 14688 grades silts between 0.002 mm and 0.063 mm. In actuality, silt is chemically distinct from clay, and unlike clay, grains of silt are approximately the same size in all dimensions; furthermore, their size ranges overlap. Clays are formed from thin plate-shaped particles held together by electrostatic forces, so present a cohesion. According to the U.S. Department of Agriculture Soil Texture Classification system, the sand-silt distinction is made at the 0.05 mm particle size. The USDA system has been adopted by the Food and Agriculture Organization (FAO). In the Unified Soil Classification System (USCS) and the AASHTO Soil Classification system, the sand-silt distinction is made at the 0.075 mm particle size (i.e., material passing the #200 sieve). Silts and clays are distinguished mechanically by their plasticity. |
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database_cross_reference |
SWEETRealm:Silt EcoLexicon:silt |
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definition |
Particulate environmental material which is primarily composed of silt particles. |
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has characteristic | ||
has part | ||
has quality | ||
label |
silt |
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overlaps | ||
prefixIRI |
ENVO:01000016 |
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prefLabel |
silt |
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disjointWith | ||
subClassOf |