Definition - What does Silt Soil mean?
Silt is a type of soil with granular particles approximately the same size as sand and clay. The origin of the soil comes from feldspar and quartz. It occurs by physical weathering and/or chemical weathering of rock. It is a very fertile soil, mainly found along river banks. When it is dry, it is light enough to be carried by the wind.
WineFrog explains Silt Soil
Silt soils are one of the more ideal soils for growing grape vines as they have the ability to retain heat and water. These soils are especially interesting in cool climates with a lot of light hours as the soil can warm up from the sunlight and allow for grape vines to have better soil temperatures to grow in.
In Washington state, Loess soils which have been wind-blown, make up the top layer of ancient flood soils below consisting of loam and sand. This soil creates wines, which have smooth tannins, are lighter in color and balanced acidity.