[meteorite-list] Des Plaines, Illinois impact crater

[Paul H.]

In Des Plaines,IL impact crater at
http://six.pairlist.net/pipermail/meteorite-list/2012-June/085848.html
Brandon D. wrote,

"Does anyone know if there are any exposures 
of impact related rock in Des Plains Illinois as 
a result of the impact 280 m.y?"

Unfortunately, this structure is completely buried by
Pleistocene glacial till. Go see:

Faulting and the Des Plaines Disturbance
http://www.isgs.uiuc.edu/maps-data-pub/cook-atlas/fault.shtml

"The faulted bedrock is buried beneath 75 to 200 feet of 
glacial drift, and the anomaly can only be studied using 
well control and seismic reflection data."

and

Emrich, G. M. and R. E. Bergstrom, 1962, Des Plaines 
Disturbance, Northeastern Illinois, Geological Society
of America Bulletin vol. 73, no. 8, pp. 959-968.

McHone, J. F., Sargent, M. L. and Nelson, W. J., 1986, 
Shatter cones in Illinois: Evidence for meteoritic 
impacts at Glasford and Des Plaines (abstract). 
Meteoritics, vol. 21, p. 446.

Peterson, G. L., 1989, Tarp Tunnel explorations in 
the Des Plaines disturbance, Illinois; evidence 
supporting an impact origin. Chicago Association 
of Engineering Geologists Annual Meeting, pp. 236-225. 

Best wishes,

Paul H.