Des Plaines - Hypervelocity Impact Crater

Alternate Names Des Plaines Structure ex: geological map by (Kolata, 2005).
Coordinates 42° 2' 22" N; 87° 52' 28" W
Notes
  1. In NW suburbs of Chicago, near the town of Des Plaines.
Country United States of America
Region Illinois
Date Confirmed 1986
Notes
  1. Confirmed by quartz grains with percussion features, strain lamellae, and occasional planar microfractures, as well as weakly developed shatter cones within dolomite beds (McHone et al., 1986).
Buried? Yes
Notes
  1. Buried by glacial drift, 15 m to 100 m thick (Emrich and Bergstrom, 1962).
Drilled? Yes
Notes
  1. Drilled for water wells and construction.
Target Type Sedimentary
Notes
  1. Cambrian-Pennsylvanian sandstones, dolomites, limestones, siltstones and shales.
Sub-Type Dolomite, Limestone, Sandstone, Shale, Siltstone
Apparent Crater Diameter (km) 8 km
Age (Ma) <299
Notes :
  1. <299 Ma is provided based on age of target rocks and the crater's burial by glacial drift (Emrich and Bergstrom, 1962).

Method :
  1. Stratigraphy
Impactor Type Unknown

Advanced Data Fields

Notes

Local Language
N/A
Erosion
6
  1. Deeply eroded; only "roots of crater remain" (Emrich and Bergstrom, 1962). Erosion has removed about 300 m of rocks since Pennsylvanian time (Willman, 1971).
Final Rim Diameter
Unknown
Apparent Rim Diameter
8 km
  1. (Flamini et al., 2019).
Rim Reliability Index
2
  1. A local zone of intense faulting, unexposed, roughly circular with central uplifted core (Langan, 1974). "The most intensive faulting has occurred near the center. Here a block capped by St. Peter Sandstone and possibly Oneota Dolomite of Middle and Early Ordovician ages has been structurally uplifted about 600 feet." (Emrich and Bergstrom, 1962) and (Willman, 1971) page 35 [which is about 183m]. "A central core of brecciated Champlainian (middle Ordovician) St. Peter Sandstone is uplifted more than 250m above normal elevation." (McHone et al., 1986).
Crater Morphology
Complex
Central Uplift Diameter
~1 km
Central Uplift Height
Unknown
Uplift Reliability Index
3
Structural Uplift
250 m
Thickness of Seds
Unknown
Target Age
Palaeozoic
Marine
No
Impactor Type
Unknown
Other Shock Metamorphism
No
Shatter Cones
Yes
  1. Occasional beds of brittle dolomite contain distinct weakly developed shatter cones (McHone et al., 1986).
Planar Fractures
No
  1. "Individual quartz grains commonly have well-developed percussion features, strain lamellae, and occasional sets of crystallographically oriented planar microfractures" (McHone et al., 1986).
Planar Deformation Features
No
  1. No PDF reported (Koeberl et al., 1996).
Diaplectic Glass
No
Coesite
No
Stisovite
No
Crater Fill
LB
  1. Structure deeply eroded. Breccia: Fig. 5 from (Emerich and Bergstrom, 1962), and (McHone et al., 1986).
Proximal Ejecta
Unknown
Distal Ejecta
Unknown
Dykes
Unknown
Volume of Melt
Unknown
Depth of Melting
Unknown

References

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C Hier, N Stephens, C F Vondra (1996) The Des Plaines disturbance; a buried impact site, Abstracts with Programs - Geological Society of America 28(6), p. 44-45, Geological Society of America (GSA), Boulder, CO, url

D R Kolata, C Nimz (2010) Geology of Illinois, Geology of Illinois, Dennis R Kolata, Cheryl K Nimz (ed.), University of Illinois at Urbana-Champaign, Institute of Natural Resource Sustainability, Champaign, IL, url

Enrico Flamini, A Coletta, M L Battagliere, M Virelli (2019) Des Plaines, USA, Encyclopedic Atlas of Terrestrial Impact Craters, p. 501-502, Springer, Cham, url