Editing 38th parallel structures (section)

{{short description|American Midwest landscape depressions}}
{{for|the manmade structures along the Korean 38th parallel|Korean Demilitarized Zone}}
{{Infobox
| image = [[File:38th parallel structures loc.svg|right|300px]]
| caption = 
{{aligned table|fullwidth=y|leftright=y|row1header = y
|Structure|Coordinates
|[[Hicks Dome]] |{{coord|37.5|N|88.3|W|name=Hicks Dome}}
|[[Avon crater|Avon]] |{{coord|37.8|N|90.2|W|name=Avon crater}}
|[[Crooked Creek crater|Crooked Creek]] |{{coord|37.8|N|91.4|W|name=Crooked Creek crater}}
|[[Decaturville crater|Decaturville]] |{{coord|37.9|N|92.7|W|name=Decaturville crater}}
|[[Hazelgreen crater|Hazelgreen]] |{{coord|37.7|N|92.4|W|name=Hazelgreen crater}}
|[[Weaubleau structure|Weaubleau-Osceola]] |{{coord|38.0|N|93.6|W|name=Weaubleau-Osceola structure}}
|[[Rose Dome]] |{{coord|37.7|N|95.7|W|name=Rose Dome}}
}} | decat = yes <!-- intentionally no data rows -->}}
{{geoGroup}}
The '''38th parallel structures''', also known as the '''38th parallel lineament''',<ref>Gillman, Joe (ed.), [http://www.missourigeologists.org/Meeting2004/AMGguidebook2004.pdf Association of Missouri Geologists Field Trip Guidebook], 51st Annual Meeting, Rolla, Missouri, October 1–2, 2004, 2004, [[Missouri Department of Natural Resources]], Geological Survey and Resource Assessment Division, p. 15</ref> are a series of seven circular depressions or deformations stretching {{convert|700|km|mi}} across southern [[Illinois]] and [[Missouri]] and into eastern [[Kansas]], in the United States, at a [[latitude]] of roughly [[38th parallel north|38 degrees north]]. Estimated at 300 million years old, three are believed to be [[impact event]]s from meteorites, but other structures are possibly remnants of [[volcano]]s.