The Sandwich Fault Zone is a
fault zone that runs northwest from
Oswego to
Ogle County, transecting
Lee County in
Northern Illinois. The fault has generally not been active, although there was a minor earthquake in 2002, and another, slightly larger one, in 2010.[1] It has a largely 400 to 600-foot vertical displacement, although parts can reach up to an 800-foot displacement, and is likely a configuration of several smaller faults, varying in both direction and displacement.[2][3]
^Morrow, William (May 2003).
"When is the next earthquake in Illinois?"(PDF). Water Resources Update – Illinois District Newsletter. US Geological Survey. pp. 4–5. Archived from
the original(PDF) on 2017-10-11. Retrieved 7 March 2010.
Kolata, Dennis R.; Buschbach, T. C.; Treworgy, Janis D. (1978). The Sandwich Fault Zone of Northern Illinois. Vol. Information circular / Illinois State Geological Survey, [no. 505]. Urbana: Illinois State Geological Survey.
hdl:
10111/UIUCOCA:sandwichfaultzon505kola.