Dennis Formation
{{short description|Geologic formation in Missouri, United States}}
{{Infobox rockunit
| name = Dennis Formation
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| type = Formation
| age = Carboniferous
| period = Carboniferous
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| region = Missouri
| country = United States
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The Dennis Formation is a geologic formation in Missouri. It preserves fossils dating back to the late Carboniferous period. The formation is part of the Kansas City Group, Missourian Stage, Pennsylvanian subperiod of the Carboniferous period.
The formation members, from bottom to top, are Canville Limestone, Stark Shale, and Winterset Limestone.
The three members form the major part of a cyclothem, created as sea water rise quickly and then gradually fall again over millions of years.
File:Kansas-Missouri-Iowa-Outcrop-Belt-Cyclothem-Outline.png
Photos
{{gallery
|title=Dennis Formation Examples
|width=160 | height=170 |noborder=yes
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|footer=Dennis Formation
|File:WintersetLS-cliff-RockIslandTrail-Frost-20230422 200738 lmc 8.4.jpg|Railroad cut showing Winterset Limestone, Dennis Formation, Upper Bronson Subgroup, Kansas City Group, Missourian Series, Pennsylvanian System. Note thin horizontal partings - very thin layers of shale separating the limestone periodically - a characteristic of many Kansas City Group limestone members. The thin shale layers represent a short period of time under different environmental conditions, or perhaps even a single catastrophic or large-scale event. Raytown, Missouri.
|Railroad cut showing Winterset Limestone, Dennis Formation, Upper Bronson Subgroup, Kansas City Group, Missourian Series, Pennsylvanian System. Note thin horizontal partings - very thin layers of shale separating the limestone periodically - a characteristic of many Kansas City Group limestones. Raytown, Missouri.
|File:WintersetLS-cliff-RockIslandTrail-Frost-LMC 20231106 163355 LMC8.3R8 Moto G Stylus 2022 first-CROP-CROP.jpg|Railroad cut showing Winterset Limestone, Dennis Formation, Upper Bronson Subgroup, Kansas City Group, Missourian Series, Pennsylvanian System. Note the Stark Shale Member beneath the limestone - the softer shale has eroded and undercut the limestone above. Raytown, Missouri.
|File:WintersetLS-RockIslTrail-Noland-LMC 20241008 184525 LMC8.3R8 Moto G Stylus 2022 first.jpg|Railroad cut showing new rockfall Winterset Limestone next to older cliffs. Note the gray color of the weathered limestone vs the buff color of the new rockfall. Raytown, Missouri.|Railroad cut showing new rockfall Winterset Limestone next to older cliffs. Note the gray color of the weathered limestone vs the buff color of the new rockfall. Raytown, Missouri.
|File:WintersetLS-detail-RockIslandTrail-Noland-IMG 20231106 164111419.jpg|Detail of Winterset Limestone, Dennis Formation, Upper Bronson Subgroup, Kansas City Group, Missourian Series, Pennsylvanian System. Raytown, Missouri.
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See also
{{Portal|Earth sciences|United States|Paleontology}}
- [https://www.youtube.com/watch?v=Y1BsbiI75xY "Life in Kansas City 300 Million of Years Ago," by Richard J. Gentile] (video)
- [https://share.mo.gov/nr/mgs/MGSData/Books/Special%20Publications/Geologic%20Field%20Trips%20in%20the%20Greater%20Kansas%20City%20Area%20(Western%20Missouri,%20Northeastern%20Kansas,%20and%20Southeastern%20Nebraska)/SP-011_Original%20Digital%20Documents/01Gentile.pdf The Geology of Kansas City (Field Trip), Richard Gentile]
- [https://share.mo.gov/nr/mgs/MGSData/Books/Special%20Publications/Geologic%20Field%20Trips%20in%20the%20Greater%20Kansas%20City%20Area%20(Western%20Missouri,%20Northeastern%20Kansas,%20and%20Southeastern%20Nebraska)/SP-011_Original%20Digital%20Documents/08Priesendorf.pdf Kansas City On the Rocks - Geological Field Trip]
- [https://ngmdb.usgs.gov/Prodesc/proddesc_79286.htm Kansas City Bedrock Geology Map]
- [https://inyo2.coffeecup.com/kansasfossils/kansasfossils.html Late Pennsylvanian Fossils in Kansas]
- List of fossiliferous stratigraphic units in Missouri
- Paleontology in Missouri
References
{{Reflist}}
- {{cite web|title= Fossilworks: Gateway to the Paleobiology Database|author= ((Various Contributors to the Paleobiology Database))|url= https://www.fossilworks.org|access-date= 17 December 2021}}
Category:Carboniferous Missouri
Category:Carboniferous southern paleotropical deposits
Category:Limestone formations of the United States
Category:Shale formations of the United States
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{{Carboniferous-stub}}