Seismotectonic maps in the vicinity of the lower Wabash Valley, Illinois, Indiana, and Kentucky - Digital Spatial Database: Paleoliquefaction locations between 1990 and 1994 in Illinois

The northern part of the map area and large adjacent regions have been severely shaken by one or more moderate to large prehistoric earthquakes. The evidence of these takes the form of paleoliquefaction features, including shaking-induced sandblows and dikes that fed them.
Over several summer field seasons from 1990 through 1994, several workers searched ditches and river banks for evidence of liquefaction. They found numerous dikes and sandblows. This database includes the locations and descriptions of dikes they observed and measured.
The most widespread paleoliquefaction is attributed to a mid-Holocene earthquake near what is now Vicennes, IN, with an estimated moment- magnitude of about 7.5. Stratigraphic, geomorphological, pedological, archealogical, and geochronologic evidence indicates that probably some of the paleoliquefaction was caused by several additional, smaller earthquakes during the Holocene and late Pleistocene.