Silt semi-arid environments that substantial quantities of silt are produced. Silt is sometimes known as "rock flour" or "stone dust", especially when produced by glacial action. Mineralogically, silt is composed mainly of quartz and feldspar. Sedimentary rock composed mainly of silt is known as siltstone. Liquefaction created by a strong earthquake is silt suspended in water that is hydrodynamically forced up from below ground level. In the Udden–Wentworth scale (due to Krumbein), silt particles range between 0.0039 and 0.0625 mm, larger than clay but smaller than sand particles. ISO 14688 grades silts between 0.002 mm and 0.063 mm (sub-divided up into
Silt, Colorado west. U.S. Route 6 is Main Street in Silt, and provides a local route parallel to I-70. According to the United States Census Bureau, the town has a total area of , of which , or 1.46%, is water. This climatic region is typified by large seasonal temperature differences, with warm to hot (and often humid) summers and cold (sometimes severely cold) winters. According to the Köppen Climate Classification system, Silt has a humid continental climate, abbreviated "Dfb" on climate maps. As of the census of 2000, there were 1,740 people, 648 households, and 452 families residing in the town.