Editing Pennyroyal Plateau

{{Short description|Physiographic region of Kentucky, US}}
[[Image:KYphysiography.svg|thumb|right|Regions of Kentucky, with the Pennyroyal Plateau shown in light brown (labeled as the Mississippi Plateau)]]
The '''Pennyroyal Plateau''' or '''Pennyroyal Region''', often spelled '''Pennyrile''',<ref>[https://www.kyatlas.com/phys-mississippian-plateau.html "Pennyrile region"] at the Kentucky Atlas and Gazetteer. Retrieved 10 March 2022.</ref> is a large [[physiography|physiographic]] region of [[Kentucky]] that features rolling hills, [[cave]]s, and [[karst]] topography in general. It is named for ''[[Hedeoma pulegioides]]'' (the American pennyroyal), a wild mint that grows in the area. It is also called the "Mississippian Plateau," for the [[Mississippian (geology)|Mississippian]] geologic age in which it was formed.<ref>{{Cite web|title=The Mississippian Plateau or Pennyroyal Region , Kentucky Geological Survey site|url=https://www.uky.edu/KGS/geoky/regionPennyroyal.html|access-date=2021-07-05|website=www.uky.edu}}</ref>

The Pennyroyal is bordered by the [[Pottsville Escarpment]] in the east.  The Pottsville Escarpment is the transition zone from the central part of Kentucky to the higher and geologically younger [[Cumberland Plateau]] in the eastern part of the state.  
The Pennyroyal is bordered on the north by [[Muldraugh Hill]], the geological escarpment that forms the transition from the geologically older [[Bluegrass region|Bluegrass]] to the Pennyroyal.  This is a series of knobs and ridges based on hard [[siltstone]]s.

The Pennyroyal is bordered on the west by the younger [[Jackson Purchase]].  The Pennyroyal is often thought by non-geologists to include the [[West Kentucky Coal Field]] of [[Pennsylvanian (geology)|Pennsylvanian]] age, located in the northwestern area of the state, as the southeastern part of the [[Illinois Basin]]. The coalfield and the Pennyroyal are of different geologic ages and are separated by the Clifty Region, largely of Pennsylvanian sandstone, occasionally [[Bitumen|bituminous]]; the boundary with the Pennyroyal is the Dripping Springs Escarpment.<ref>{{Cite web|title=Geology of Kentucky: Chapter 15, Mississippian Plateaus|url=http://www.uky.edu/OtherOrgs/KPS/goky/pages/gokych15.htm|access-date=2021-07-05|website=www.uky.edu}}</ref>

To the south, the Pennyroyal continues as the [[Highland Rim]] of [[Middle Tennessee]], to the north it continues as the [[Indiana Uplands]] of [[Southern Indiana]].

The Pennyroyal is largely in farmland where the bedrock is [[limestone]], and most of the Pennyroyal is based on Mississippian limestone, particularly the [[St. Louis Limestone]] or [[Ste. Genevieve Limestone]].  In some areas, the limestone is capped with a soft sandstone.  This kind of formation is featured in the [[Mammoth Cave]] area, and has enabled the formation of the world's most extensive [[cave]] system.  Numerous other caves exist in the Pennyroyal, where some of the most intensely cave-forming limestones of the world are to be found.<ref>{{Cite web|title=Interior Low Plateaus Province (U.S. National Park Service)|url=https://www.nps.gov/articles/interiorlowplateausprovince.htm|access-date=2021-07-05|website=www.nps.gov|language=en}}</ref>

Where the capping sandstone is intact, the land surface is usually forested, rugged hills.

==References==

{{Portal|Kentucky}}
{{Reflist}}
==Further reading==
* WPA, ''Kentucky: A Guide to the Bluegrass State '' (1939); classic guide from the Federal Writers Project; covers main themes and describes every town and feature, with capsule histories [https://archive.org/details/kentuckyguidetob00federich/page/n8/mode/1up online]

{{Kentucky}}

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[[Category:Regions of Kentucky]]
[[Category:Plateaus of the United States]]
[[Category:Landforms of Kentucky]]