Gravel areas where there is little traffic. Globally, far more roads are surfaced with gravel than with concrete or tarmac; Russia alone has over of gravel roads. Both sand and small gravel are also important for the manufacture of concrete. Large gravel deposits are a common geological feature, being formed as a result of the weathering and erosion of rocks. The action of rivers and waves tends to pile up gravel in large accumulations. This can sometimes result in gravel becoming compacted and lithified into the sedimentary rock called conglomerate. Where natural gravel deposits are insufficient for human purposes, gravel is
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.