High Quality Content by WIKIPEDIA articles! A clastic dike is a seam of sedimentary material that fills a crack in and cuts across sedimentary strata or other rock types. Clastic dikes form rapidly by fluidized injection (mobilization of pressurized pore fluids) or passively by water, wind, and gravity (sediment swept into open cracks). Diagenesis may play a role in the formation of some dikes. Clastic dikes are commonly vertical or near-vertical. Centimetre-scale widths are common, but thicknesses range from millimetres to metres. Length is usually many times width.