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Silt may occur as a soil (often mixed with sand or clay) or as sediment mixed in suspension with water. Silt usually has a floury feel when dry, and lacks plasticity when wet. Silt can also be felt by the tongue as granular when placed on the front teeth (even when mixed with clay particles). Silt is a common material, making up 45% of average ...
Sedimentation in deltas also occurs in rhythmic patterns as in the lake deposits, but they are thicker and contain coarse-grained materials instead of just silt and clay. As the varves get closer to the shoreline the clay layer will stay relatively the same thickness, but there will be an increase in thickness of the silt layer.
In order for a rock to be named a siltstone, it must contain over fifty percent silt-sized material. Silt is any particle smaller than sand, 1/16 of a millimeter, and larger than clay, 1/256 of millimeter. Silt is believed to be the product of physical weathering, which can involve freezing and thawing, thermal expansion, and release of pressure.
Quicksand (also known as sinking sand) is a colloid consisting of fine granular material (such as sand, silt or clay) and water. It forms in saturated loose sand when the sand is suddenly agitated. When water in the sand cannot escape, it creates a liquefied soil that loses strength and cannot support weight.
Loam soils can be classified into more specific subtypes. Some examples are sandy loam, silt loam, clay loam, and silty clay loam. Different soil phases have some variation in characteristics like stoniness and erosion that are too minor to affect native vegetative growth but can be significant for crop cultivation. [3]
For example, GW-GM corresponds to "well-graded gravel with silt." If the soil has more than 15% by weight retained on a #4 sieve (R #4 > 15%), there is a significant amount of gravel, and the suffix "with gravel" may be added to the group name, but the group symbol does not change. For example, SP-SM could refer to "poorly graded SAND with silt ...
One common requirement is that a mudstone is a mudrock (a rock containing more than 50% silt- to clay-sized particles) in which between a third and two-thirds of the mud (silt and clay) fraction is clay particles. [7] [8] Another definition is that mudstone is a sedimentary rock in which neither silt, clay, nor coarser grains is predominant. [9]
Mud (probably from Middle Low German mudde, mod(de) 'thick mud', or Middle Dutch) [1] is loam, silt or clay mixed with water. It is usually formed after rainfall or near water sources. Ancient mud deposits hardened over geological time to form sedimentary rock such as shale or mudstone (generally called lutites ).