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Loess
Sediment of accumulated wind-blown dust / From Wikipedia, the free encyclopedia
This article is about the geologic material. For the statistical technique, see local regression.
A loess (US: /ˈlɛs, ˈlʌs, ˈloʊ.əs/, UK: /ˈloʊ.əs, ˈlɜːs/; from German: Löss [lœs]) is a clastic, predominantly silt-sized sediment that is formed by the accumulation of wind-blown dust.[1] Ten percent of Earth's land area is covered by loesses or similar deposits.[2]
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A loess is a periglacial or aeolian (windborne) sediment, defined as an accumulation of 20% or less of clay with a balance of roughly equal parts sand and silt (with a typical grain size from 20 to 50 micrometers),[3][4] often loosely cemented by calcium carbonate. Usually, they are homogeneous and highly porous and have vertical capillaries that permit the sediment to fracture and form vertical bluffs.