11. Now that you are versed in the processes that form liquefaction features, let us look at some actual examples. We will look at field examples from three areas in the United States where extensive field paleoliquefaction studies have been conducted: the New Madrid seismic zone in Missouri; the Wabash Valley seismic zone in Indiana-Illinois; and the vicinity of Charleston, South Carolina.

The New Madrid seismic zone was chosen because it was the locale of three great (M~8 or higher) earthquakes in 1811-1812, in which tremendous liquefaction occurred over a huge region. The meizoseismal zone of these earthquakes is undoubtedly one of the best places on Earth to see and study the effects of liquefaction because of the presence of widespread liquefaction and because of the availability of ditches that permit viewing in vertical section. The Wabash Valley seismic zone was chosen because recent paleoliquefaction studies provide an excellent example of how to estimate the magnitude of prehistoric earthquakes. The South Carolina study provides an excellent example of the morphology of liquefaction features where the cap has been moderately cemented by chemical weathering and the source sand is highly susceptible to liquefaction.