Incremental growth of a sheeted clastic dike occurs over time, megaflood by megaflood. The figure above shows the growth of a composite clastic dike over the course of 9 separate Ice Age megafloods. A few things to note about these crack-and-fill structures: a.) The dikes are sediment-filled fractures that widened and deepened by the addition of new fill material in pulses ("fill bands" = "dikelets" = "sheets"). b.) The propagation and geometry of the dikes are governed by pr

Truncations control dike width and apparent taper direction. What appears to be an upward-tapering, upward-injected clastic dike sourced ostensibly from a liquefied bed at depth is actually a sheeted, downward-intruded (per descendum) dike that has been partially truncated at several bedding contacts. Four flood beds are shown (A, B,C,D). They are unconsolidated, late Pleistocene rhythmites (Touchet Beds) composed of coarse sand to silt (coarse-grained bottoms, fine-grained t