Clastic dike
![Vertical clastic dike, filled with coarse basaltic sand, cuts lighter-colored horizontal beds composed of finer grained material. Quarter for scale.](/Images/godic/202502/09/Coarse_sand_dike_Starbuck0709.JPG")
![Red-colored clastic dikes injected downward into light-colored sediment beneath a debris flow. Black Dragon Wash, San Rafael Swell, Utah](/Images/godic/202502/09/Dikes_in_black_dragon_canyon_UT0709.JPG")
![Clastic dike exposed on the east flank of the central peak of Upheaval Dome, Canyonlands, Utah. The sandstone dike was injected downsection from the White Rim Sandstone into the Organ Rock Shale during the earliest part of the impact crater excavation stage. The dike is made of cataclastically broken sand grains derived from the White Rim Sandstone. The slightly overturned Organ Rock beds dip steeply to the left and their tops face toward the right. The White Rim Sandstone, folded to vertical, lies just off the photo to the right. View is to the north. P.W. Huntoon Collection.](/Images/godic/202502/09/Upheaval_dome_clastic_dike1_PWH0709.jpg")
![Vertically sheeted clastic dike typical of those found in rhythmically bedded Missoula flood slackwater deposits of the Columbia Basin. Yellow field book for scale. Willow Creek Valley at Cecil, OR.](/Images/godic/202502/09/Clastic_dike_at_cecil_swc0709.jpg")
A clastic dike is a seam of sedimentary material that fills an open fracture in and cuts across sedimentary rock strata or layering in 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. Centimeter-scale widths are common, but thicknesses range from millimetres to metres. Length is usually many times width.