6. The larger clastic dikes typically form by one of three processes, especially during severe liquefaction caused by stronger earthquakes: hydraulic fracturing, lateral spreading, and surface oscillations. (There are other means for forming clastic dikes such as venting through cracks formed by weathering, but the three mechanisms cited previously encompass the great majority of cases.) In a fine-grained cap, dikes from all these mechanisms are almost always tabular or nearly so in plan view and have a width that is a small fraction of the length in plan view. (The chief exceptions are the following: (1) where the base of the cap is extremely soft -- soft enough that a clenched hand can be forced tens of centimeters into the cap -- in which case the dike can be more or less equidimensional or even circular in cross section and may follow a tortuous path upward for as much as a few meters, and (2) where there are preexisting holes along the base of the cap that form ready-made paths for venting of weakly pressurized, yet still fluidized sediment).