Des Plaines crater

Template:Short description Template:Infobox terrestrial impact site The Des Plaines crater or Des Plaines disturbance is recognized as an impact crater in Cook County, Illinois, United States. It is located beneath the eastern part of the city of Des Plaines, which is a suburb of Chicago.<ref name=Wiggers>Template:Cite book</ref><ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref>

The Des Plaines crater is Template:Convert in diameter and covers an area of approximately Template:Convert.<ref name=IGS/> The age of the crater is unknown but is thought to be between 280 million years and 2 million years (Permian or younger).<ref>Template:Cite news</ref> The crater is buried beneath 75 to 200 feet (23–60 m) of glacial till and can only be seen as a series of faults and deformations in well logs and seismic surveys.<ref name=IGS>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> Faulting in the structure has produced as much as Template:Convert of vertical displacement.<ref name=IGS/> Subsurface strata of Cambrian through Pennsylvanian age has been faulted and tilted by the event.<ref name=Wiggers/><ref name=GSA>Template:Cite journal</ref> The anomalous area was first noted by water well drillers in 1893, who noted an absence of water in a Template:Convert deep well. Prior to being recognized as an impact structure, the feature was referred to as a cryptoexplosion structure or cryptovolcanic structure, as were several others in the Midwestern United States.<ref name=GSA/> The upfaulted central portion<ref name=GSA/> and the presence of shatter cone structures support the impact origin.<ref name=Wiggers/>

External links

• Aerial Exploration of the Des Plaines Impact Structure