Structural Features in Illinois: Faults

These data are for use at a scale of 1:500,000 or smaller only. They are appropriate for use in regional thematic analysis, for display purposes, and for mapping environmental phenomena related to them. This is a partial representation of Plate 1 from ISGS Bulletin 100 (1993). Features depicted are limited to well documented, significant faults, faulted flexures and grabens in Illinois. Names of the features and the associated directions of faulting are included. This data set must be used in conjunction with the companion data sets STRUCTCLINES, STRUCTPNTS and STRUCTPOLY for a full representation of Plate 1 of ISGS Bulletin 100.