Silt. Silt is granular material of a size somewhere between sand and clay whose mineral origin is quartz and feldspar. Silt may occur as a soil or as suspended sediment in a surface water body. It may also exist as soil deposited at the bottom of a water body.
In North America, a grade-separated junction may be referred to as a grade separation or as an interchange â in contrast with an intersection, at-grade, a diamond crossing or a level crossing, which are not grade-separated. 1 Effects.
Definition of grade. 1  1a (1) : a position in a scale of ranks or qualities (2) : a stage in a processb : a degree of severity in illness grade III carcinomac : a class organized for the work of a particular year of a school coursed : a military or naval rank.