Earth:Pocono Formation

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Pocono Formation
Stratigraphic range: Early Mississippian
Ricketts Glen State Park Pocono Formation.jpg
Outcrop at Ricketts Glen State Park
Typesedimentary
UnderliesMauch Chunk Formation
OverliesCatskill Formation, Huntley Mountain Formation, Rockwell Formation, and Spechty Kopf Formation
Lithology
PrimaryQuartzarenite (sandstone)
OtherConglomerate
Location
RegionAppalachian Mountains
ExtentPennsylvania and Virginia[1]
Type section
Named byLesley, 1876

The Mississippian Pocono Formation is a mapped bedrock unit in Pennsylvania, Maryland, and West Virginia, in the United States. It is also known as the Pocono Group in Maryland and West Virginia,[2] and the upper part of the Pocono Formation is sometimes called the Burgoon Formation or Burgoon Sandstone in Pennsylvania.[3][4] The Pocono is a major ridge-former In the Ridge-and-Valley Appalachians of the eastern United States [5]

The Pocono is also a lateral equivalent of the Purslane Sandstone in Maryland and West Virginia. D. Brezinski of Maryland Geological Survey recommended abandoning use of the term Pocono in Maryland in favor of "Purslane" in 1989.[6]

Description

The Pocono is a dominantly gray color with quartzitic medium to coarse-grained sandstones. The base of the Pocono Formation is marked by conglomerate.[7]

Sideling Hill roadcut

Notable exposures

  • The type section of the Burgoon Sandstone is in the valley of Burgoon Run, above Kittanning Point, Blair County, Pennsylvania.
  • A spectacular exposure of the Purslane Sandstone (equivalent to the Pocono) is at the I-68 road cut through Sideling Hill in Maryland.

Age

Relative age dating of the Pocono places it in the lower Mississippian period. The lower boundary is with the Spetchy Kopf Formation and Huntley Mountain Formation. In South-central Pennsylvania, the Pocono often interfingers with the Rockwell Formation.[8]

See also

  • Geology of Pennsylvania
  • Canaan Valley

References

  1. Paleozoic Sedimentary Successions of the Virginia Valley & Ridge and Plateau
  2. "Geologic Maps of Maryland:". http://www.mgs.md.gov/esic/geo/lgdalleg.html. Retrieved January 31, 2024. 
  3. Van Diver, Bradford B. (1990). Roadside Geology of Pennsylvania. Missoula, Montana: Mountain Press Publishing Company. pp. 83. ISBN 0-87842-227-7. 
  4. "Burgoon Sandstone". United States Geological Survey. May 22, 2009. https://mrdata.usgs.gov/geology/state/sgmc-unit.php?unit=PAMb%3B10. 
  5. Kempler, Steve (2007-01-19). "Geomorphology : Chapter 2 Plate T-12 : Folded Appalachians". NASA, Goddard Earth Sciences (GES), Data and Information Services Center (DISC). http://daac.gsfc.nasa.gov/geomorphology/GEO_2/GEO_PLATE_T-12.shtml. "The major ridge makers are the Tuscarora (T), Pocono (Po), and Pottsville (Pt) Formations." 
  6. Brezinski, D.K., 1989, The Mississippian System in Maryland: Maryland Geological Survey Report of Investigations, no. 52, 75 p.
  7. "Geology : Pocono (Mp)". LEO EnviroSci Inquiry. Lehigh University. http://www.leo.lehigh.edu/envirosci/geology/gorge/m_p.html. 
  8. Berg, T.M., Edmunds, W.E., Geyer, A.R. and others, compilers, (1980). Geologic Map of Pennsylvania: Pennsylvania Geologic Survey, Map 1, scale 1:250,000.

External links